diff --git a/apps/visualizer/.env.example b/apps/visualizer/.env.example
index 9e85877..75c30ad 100644
--- a/apps/visualizer/.env.example
+++ b/apps/visualizer/.env.example
@@ -1,11 +1,13 @@
 # Default: UI reads ticks from the same-origin API proxy at `/api`.
 VITE_API_URL=/api
 
-# Fallback (optional): query Hasura directly (not recommended in browser).
-VITE_HASURA_URL=http://localhost:8080/v1/graphql
-# Optional (only if you intentionally query Hasura directly from the browser):
+# Hasura GraphQL endpoint (supports subscriptions via WS).
+# On VPS, `trade-frontend` proxies Hasura at the same origin under `/graphql`.
+VITE_HASURA_URL=/graphql
+# Optional explicit WS URL; when omitted the app derives it from `VITE_HASURA_URL`.
+# VITE_HASURA_WS_URL=wss://YOUR_HOST/graphql
+# Optional auth (only if Hasura is not configured with `HASURA_GRAPHQL_UNAUTHORIZED_ROLE=public`):
 # VITE_HASURA_AUTH_TOKEN=YOUR_JWT
-# VITE_HASURA_ADMIN_SECRET=devsecret
 VITE_SYMBOL=PUMP-PERP
 # Optional: filter by source (leave empty for all)
 # VITE_SOURCE=drift_oracle
diff --git a/apps/visualizer/__start b/apps/visualizer/__start
new file mode 100644
index 0000000..bd85039
--- /dev/null
+++ b/apps/visualizer/__start
@@ -0,0 +1 @@
+API_PROXY_TARGET=https://trade.mpabi.pl GRAPHQL_PROXY_TARGET=https://trade.mpabi.pl npm run dev
diff --git a/apps/visualizer/src/App.tsx b/apps/visualizer/src/App.tsx
index 5e529b3..bb997ca 100644
--- a/apps/visualizer/src/App.tsx
+++ b/apps/visualizer/src/App.tsx
@@ -11,6 +11,7 @@ import Button from './ui/Button';
 import TopNav from './layout/TopNav';
 import AuthStatus from './layout/AuthStatus';
 import LoginScreen from './layout/LoginScreen';
+import { useDlobStats } from './features/market/useDlobStats';
 
 function envNumber(name: string, fallback: number): number {
   const v = (import.meta as any).env?.[name];
@@ -99,7 +100,7 @@ export default function App() {
 }
 
 function TradeApp({ user, onLogout }: { user: string; onLogout: () => void }) {
-  const markets = useMemo(() => ['PUMP-PERP', 'SOL-PERP', 'BTC-PERP', 'ETH-PERP'], []);
+  const markets = useMemo(() => ['PUMP-PERP', 'SOL-PERP', 'BONK-PERP', 'BTC-PERP', 'ETH-PERP'], []);
 
   const [symbol, setSymbol] = useLocalStorageState('trade.symbol', envString('VITE_SYMBOL', 'PUMP-PERP'));
   const [source, setSource] = useLocalStorageState('trade.source', envString('VITE_SOURCE', ''));
@@ -128,6 +129,8 @@ function TradeApp({ user, onLogout }: { user: string; onLogout: () => void }) {
     pollMs,
   });
 
+  const { stats: dlob, connected: dlobConnected, error: dlobError } = useDlobStats(symbol);
+
   const latest = candles.length ? candles[candles.length - 1] : null;
   const first = candles.length ? candles[0] : null;
   const changePct =
@@ -209,12 +212,22 @@ function TradeApp({ user, onLogout }: { user: string; onLogout: () => void }) {
           ),
       },
       { key: 'oracle', label: 'Oracle', value: formatUsd(latest?.oracle ?? null) },
-      { key: 'funding', label: 'Funding / 24h', value: '—', sub: '—' },
-      { key: 'oi', label: 'Open Interest', value: '—' },
-      { key: 'vol', label: '24h Volume', value: '—' },
-      { key: 'details', label: 'Market Details', value: <a href="#">View</a> },
+      { key: 'bid', label: 'Bid', value: formatUsd(dlob?.bestBid ?? null) },
+      { key: 'ask', label: 'Ask', value: formatUsd(dlob?.bestAsk ?? null) },
+      {
+        key: 'spread',
+        label: 'Spread',
+        value: dlob?.spreadBps == null ? '—' : `${dlob.spreadBps.toFixed(1)} bps`,
+        sub: formatUsd(dlob?.spreadAbs ?? null),
+      },
+      {
+        key: 'dlob',
+        label: 'DLOB',
+        value: dlobConnected ? 'live' : '—',
+        sub: dlobError ? <span className="neg">{dlobError}</span> : dlob?.updatedAt || '—',
+      },
     ];
-  }, [latest?.close, latest?.oracle, changePct]);
+  }, [latest?.close, latest?.oracle, changePct, dlob, dlobConnected, dlobError]);
 
   const seriesLabel = useMemo(() => `Candles: Mark (oracle overlay)`, []);
   const seriesKey = useMemo(() => `${symbol}|${source}|${tf}`, [symbol, source, tf]);
diff --git a/apps/visualizer/src/features/chart/TradingChart.tsx b/apps/visualizer/src/features/chart/TradingChart.tsx
index cfecb61..d05e355 100644
--- a/apps/visualizer/src/features/chart/TradingChart.tsx
+++ b/apps/visualizer/src/features/chart/TradingChart.tsx
@@ -1,13 +1,18 @@
-import { useEffect, useMemo, useRef } from 'react';
+import { useEffect, useMemo, useRef, useState } from 'react';
 import {
   CandlestickSeries,
   ColorType,
   CrosshairMode,
   HistogramSeries,
+  type IPrimitivePaneRenderer,
+  type IPrimitivePaneView,
   type IChartApi,
   type ISeriesApi,
+  type ISeriesPrimitive,
   LineStyle,
   LineSeries,
+  type SeriesAttachedParameter,
+  type Time,
   createChart,
   type UTCTimestamp,
   type CandlestickData,
@@ -49,6 +54,13 @@ type Props = {
 type LinePoint = LineData | WhitespaceData;
 type BuildSample = { t: number; v: number };
 
+const BUILD_UP_COLOR = '#22c55e';
+const BUILD_DOWN_COLOR = '#ef4444';
+const BUILD_FLAT_COLOR = '#60a5fa';
+const BUILD_UP_SLICE = 'rgba(34,197,94,0.70)';
+const BUILD_DOWN_SLICE = 'rgba(239,68,68,0.70)';
+const BUILD_FLAT_SLICE = 'rgba(96,165,250,0.70)';
+
 function toTime(t: number): UTCTimestamp {
   return t as UTCTimestamp;
 }
@@ -110,6 +122,258 @@ function toLineSeries(points: SeriesPoint[] | undefined): LinePoint[] {
   return points.map((p) => (p.value == null ? ({ time: toTime(p.time) } as WhitespaceData) : { time: toTime(p.time), value: p.value }));
 }
 
+function colorForDelta(delta: number): string {
+  if (delta > 0) return BUILD_UP_COLOR;
+  if (delta < 0) return BUILD_DOWN_COLOR;
+  return BUILD_FLAT_COLOR;
+}
+
+function sliceColorForDelta(delta: number): string {
+  if (delta > 0) return BUILD_UP_SLICE;
+  if (delta < 0) return BUILD_DOWN_SLICE;
+  return BUILD_FLAT_SLICE;
+}
+
+type SliceDir = -1 | 0 | 1;
+
+function dirForDelta(delta: number): SliceDir {
+  if (delta > 0) return 1;
+  if (delta < 0) return -1;
+  return 0;
+}
+
+function buildDeltaSeriesForCandle(candle: Candle, bs: number, samples: BuildSample[] | undefined): LinePoint[] {
+  const eps = 1e-3;
+  const startT = candle.time + eps;
+  const endT = candle.time + bs - eps;
+  if (!(endT > startT)) return [];
+
+  const points: BuildSample[] = [{ t: startT, v: 0 }];
+  let lastT = startT;
+  for (const p of samples || []) {
+    let t = p.t;
+    if (t <= lastT + eps) t = lastT + eps;
+    if (t >= endT) break;
+    points.push({ t, v: p.v });
+    lastT = t;
+  }
+
+  const finalDelta = candle.close - candle.open;
+  if (endT > lastT + eps) {
+    points.push({ t: endT, v: finalDelta });
+  } else if (points.length) {
+    points[points.length - 1] = { ...points[points.length - 1]!, v: finalDelta };
+  }
+
+  const out: LinePoint[] = [{ time: toTime(candle.time) } as WhitespaceData];
+  out.push({ time: toTime(points[0]!.t), value: points[0]!.v } as LineData);
+
+  let lastLineIdx = out.length - 1;
+  let lastVal = points[0]!.v;
+  for (let i = 1; i < points.length; i += 1) {
+    const v = points[i]!.v;
+    const prev = out[lastLineIdx] as LineData;
+    out[lastLineIdx] = { ...prev, color: colorForDelta(v - lastVal) } as LineData;
+    out.push({ time: toTime(points[i]!.t), value: v } as LineData);
+    lastLineIdx = out.length - 1;
+    lastVal = v;
+  }
+  return out;
+}
+
+type BuildSlicesState = {
+  enabled: boolean;
+  candles: Candle[];
+  bucketSeconds: number;
+  samples: Map<number, BuildSample[]>;
+  series: ISeriesApi<'Histogram', Time> | null;
+  chart: SeriesAttachedParameter<Time>['chart'] | null;
+};
+
+class BuildSlicesPaneRenderer implements IPrimitivePaneRenderer {
+  private readonly _getState: () => BuildSlicesState;
+
+  constructor(getState: () => BuildSlicesState) {
+    this._getState = getState;
+  }
+
+  draw(target: any) {
+    const { enabled, candles, bucketSeconds, samples, series, chart } = this._getState();
+    if (!enabled) return;
+    if (!candles.length || !series || !chart) return;
+
+    const bs = resolveBucketSeconds(bucketSeconds, candles);
+    const rows = Math.min(60, Math.max(12, Math.floor(bs)));
+    const lastCandleTime = candles[candles.length - 1]?.time ?? null;
+
+    const yBase = series.priceToCoordinate(0);
+    if (yBase == null) return;
+
+    const xs = candles.map((c) => chart.timeScale().timeToCoordinate(toTime(c.time)));
+
+    target.useBitmapCoordinateSpace(({ context, bitmapSize, horizontalPixelRatio, verticalPixelRatio }: any) => {
+      const yBottomPx = Math.round(yBase * verticalPixelRatio);
+      const lastIdx = xs.length - 1;
+
+      for (let i = 0; i < candles.length; i += 1) {
+        const x = xs[i];
+        if (x == null) continue;
+        if (!Number.isFinite(x)) continue;
+
+        const c = candles[i]!;
+        const list = samples.get(c.time);
+        const start = c.time;
+        const end = start + bs;
+        const isCurrent = lastCandleTime != null && c.time === lastCandleTime;
+        const now = Date.now() / 1000;
+        const progressT = isCurrent ? Math.min(end, Math.max(start, now)) : end;
+
+        let spacing = 0;
+        const prevX = i > 0 ? xs[i - 1] : null;
+        const nextX = i < lastIdx ? xs[i + 1] : null;
+        if (prevX != null && Number.isFinite(prevX)) spacing = x - prevX;
+        if (nextX != null && Number.isFinite(nextX)) {
+          const s2 = nextX - x;
+          spacing = spacing > 0 ? Math.min(spacing, s2) : s2;
+        }
+        if (!(spacing > 0)) spacing = 6;
+
+        const barWidthCss = Math.max(1, spacing * 0.9);
+        const barWidthPx = Math.max(1, Math.round(barWidthCss * horizontalPixelRatio));
+        const xCenterPx = Math.round(x * horizontalPixelRatio);
+        const xLeftPx = Math.round(xCenterPx - barWidthPx / 2);
+
+        const volumeValue = typeof c.volume === 'number' && Number.isFinite(c.volume) ? c.volume : 0;
+        if (!(volumeValue > 0)) continue;
+        const yTop = series.priceToCoordinate(volumeValue);
+        if (yTop == null) continue;
+        const yTopPx = Math.round(yTop * verticalPixelRatio);
+        if (!(yBottomPx > yTopPx)) continue;
+        const barHeightPx = yBottomPx - yTopPx;
+
+        const rowDirs: Array<SliceDir | null> = Array.from({ length: rows }, () => null);
+        const overallDir = dirForDelta(c.close - c.open);
+
+        const points: BuildSample[] = [{ t: start, v: 0 }];
+        if (list?.length) {
+          for (const p of list) {
+            if (!Number.isFinite(p.t) || !Number.isFinite(p.v)) continue;
+            const t = Math.min(end, Math.max(start, p.t));
+            points.push({ t, v: p.v });
+          }
+        }
+
+        const endV = c.close - c.open;
+        const lastPt = points[points.length - 1]!;
+        if (progressT > lastPt.t + 1e-3) {
+          points.push({ t: progressT, v: endV });
+        } else {
+          lastPt.v = endV;
+        }
+
+        for (let j = 1; j < points.length; j += 1) {
+          const a = points[j - 1]!;
+          const b = points[j]!;
+          const dir = dirForDelta(b.v - a.v);
+
+          const from = Math.max(0, Math.min(rows - 1, Math.floor(((a.t - start) / bs) * rows)));
+          const to = Math.max(0, Math.min(rows - 1, Math.floor(((b.t - start) / bs) * rows)));
+
+          for (let r = from; r <= to; r += 1) rowDirs[r] = dir;
+        }
+
+        const progressRows = Math.max(0, Math.min(rows, Math.ceil(((progressT - start) / bs) * rows)));
+        for (let r = 0; r < progressRows; r += 1) {
+          if (rowDirs[r] == null) rowDirs[r] = overallDir;
+        }
+
+        const x0 = Math.max(0, Math.min(bitmapSize.width, xLeftPx));
+        const x1 = Math.max(0, Math.min(bitmapSize.width, xLeftPx + barWidthPx));
+        const w = x1 - x0;
+        if (!(w > 0)) continue;
+
+        for (let r = 0; r < progressRows; r += 1) {
+          const dir = rowDirs[r];
+          if (dir == null) continue;
+
+          const rowTop = yBottomPx - Math.round(((r + 1) * barHeightPx) / rows);
+          const rowBottom = yBottomPx - Math.round((r * barHeightPx) / rows);
+          const h = rowBottom - rowTop;
+          if (!(h > 0)) continue;
+
+          context.fillStyle = sliceColorForDelta(dir);
+          context.fillRect(x0, rowTop, w, h);
+        }
+      }
+    });
+  }
+}
+
+class BuildSlicesPaneView implements IPrimitivePaneView {
+  private readonly _renderer: BuildSlicesPaneRenderer;
+
+  constructor(getState: () => BuildSlicesState) {
+    this._renderer = new BuildSlicesPaneRenderer(getState);
+  }
+
+  zOrder() {
+    return 'top';
+  }
+
+  renderer() {
+    return this._renderer;
+  }
+}
+
+class BuildSlicesPrimitive implements ISeriesPrimitive<Time> {
+  private _param: SeriesAttachedParameter<Time> | null = null;
+  private _series: ISeriesApi<'Histogram', Time> | null = null;
+  private _enabled = true;
+  private _candles: Candle[] = [];
+  private _bucketSeconds = 0;
+  private _samples: Map<number, BuildSample[]> = new Map();
+  private readonly _paneView: BuildSlicesPaneView;
+  private readonly _paneViews: readonly IPrimitivePaneView[];
+
+  constructor() {
+    this._paneView = new BuildSlicesPaneView(() => ({
+      enabled: this._enabled,
+      candles: this._candles,
+      bucketSeconds: this._bucketSeconds,
+      samples: this._samples,
+      series: this._series,
+      chart: this._param?.chart ?? null,
+    }));
+    this._paneViews = [this._paneView];
+  }
+
+  attached(param: SeriesAttachedParameter<Time>) {
+    this._param = param;
+    this._series = param.series as ISeriesApi<'Histogram', Time>;
+  }
+
+  detached() {
+    this._param = null;
+    this._series = null;
+  }
+
+  paneViews() {
+    return this._paneViews;
+  }
+
+  setEnabled(next: boolean) {
+    this._enabled = Boolean(next);
+    this._param?.requestUpdate();
+  }
+
+  setData(next: { candles: Candle[]; bucketSeconds: number; samples: Map<number, BuildSample[]> }) {
+    this._candles = Array.isArray(next.candles) ? next.candles : [];
+    this._bucketSeconds = Number.isFinite(next.bucketSeconds) ? next.bucketSeconds : 0;
+    this._samples = next.samples;
+    this._param?.requestUpdate();
+  }
+}
+
 export default function TradingChart({
   candles,
   oracle,
@@ -136,18 +400,22 @@ export default function TradingChart({
   const fibOpacityRef = useRef<number>(fibOpacity);
   const priceAutoScaleRef = useRef<boolean>(priceAutoScale);
   const prevPriceAutoScaleRef = useRef<boolean>(priceAutoScale);
+  const showBuildRef = useRef<boolean>(showBuild);
   const onReadyRef = useRef<Props['onReady']>(onReady);
   const onChartClickRef = useRef<Props['onChartClick']>(onChartClick);
   const onChartCrosshairMoveRef = useRef<Props['onChartCrosshairMove']>(onChartCrosshairMove);
   const onPointerEventRef = useRef<Props['onPointerEvent']>(onPointerEvent);
   const capturedOverlayPointerRef = useRef<number | null>(null);
+  const buildSlicesPrimitiveRef = useRef<BuildSlicesPrimitive | null>(null);
   const buildSamplesRef = useRef<Map<number, BuildSample[]>>(new Map());
   const buildKeyRef = useRef<string | null>(null);
   const lastBuildCandleStartRef = useRef<number | null>(null);
+  const hoverCandleTimeRef = useRef<number | null>(null);
+  const [hoverCandleTime, setHoverCandleTime] = useState<number | null>(null);
   const seriesRef = useRef<{
     candles?: ISeriesApi<'Candlestick'>;
     volume?: ISeriesApi<'Histogram'>;
-    build?: ISeriesApi<'Line'>;
+    buildHover?: ISeriesApi<'Line'>;
     oracle?: ISeriesApi<'Line'>;
     sma20?: ISeriesApi<'Line'>;
     ema20?: ISeriesApi<'Line'>;
@@ -198,6 +466,14 @@ export default function TradingChart({
     priceAutoScaleRef.current = priceAutoScale;
   }, [priceAutoScale]);
 
+  useEffect(() => {
+    showBuildRef.current = showBuild;
+    if (!showBuild && (hoverCandleTimeRef.current != null || hoverCandleTime != null)) {
+      hoverCandleTimeRef.current = null;
+      setHoverCandleTime(null);
+    }
+  }, [showBuild, hoverCandleTime]);
+
   useEffect(() => {
     if (!containerRef.current) return;
     if (chartRef.current) return;
@@ -249,8 +525,13 @@ export default function TradingChart({
       scaleMargins: { top: 0.88, bottom: 0 },
     });
 
-    const buildSeries = chart.addSeries(LineSeries, {
-      color: '#60a5fa',
+    const buildSlicesPrimitive = new BuildSlicesPrimitive();
+    volumeSeries.attachPrimitive(buildSlicesPrimitive);
+    buildSlicesPrimitiveRef.current = buildSlicesPrimitive;
+    buildSlicesPrimitive.setEnabled(!showBuildRef.current);
+
+    const buildHoverSeries = chart.addSeries(LineSeries, {
+      color: BUILD_FLAT_COLOR,
       lineWidth: 2,
       priceFormat,
       priceScaleId: 'build',
@@ -258,7 +539,7 @@ export default function TradingChart({
       priceLineVisible: false,
       crosshairMarkerVisible: false,
     });
-    buildSeries.priceScale().applyOptions({
+    buildHoverSeries.priceScale().applyOptions({
       scaleMargins: { top: 0.72, bottom: 0.12 },
       visible: false,
       borderVisible: false,
@@ -285,7 +566,7 @@ export default function TradingChart({
     seriesRef.current = {
       candles: candleSeries,
       volume: volumeSeries,
-      build: buildSeries,
+      buildHover: buildHoverSeries,
       oracle: oracleSeries,
       sma20: smaSeries,
       ema20: emaSeries,
@@ -335,7 +616,23 @@ export default function TradingChart({
     chart.subscribeClick(onClick);
 
     const onCrosshairMove = (param: any) => {
-      if (!param?.point) return;
+      if (!param?.point) {
+        if (showBuildRef.current && hoverCandleTimeRef.current != null) {
+          hoverCandleTimeRef.current = null;
+          setHoverCandleTime(null);
+        }
+        return;
+      }
+
+      if (showBuildRef.current) {
+        const t = typeof param?.time === 'number' ? Number(param.time) : null;
+        const next = t != null && Number.isFinite(t) ? t : null;
+        if (hoverCandleTimeRef.current !== next) {
+          hoverCandleTimeRef.current = next;
+          setHoverCandleTime(next);
+        }
+      }
+
       const logical = param.logical ?? chart.timeScale().coordinateToLogical(param.point.x);
       if (logical == null) return;
       const price = candleSeries.coordinateToPrice(param.point.y);
@@ -580,6 +877,10 @@ export default function TradingChart({
         candleSeries.detachPrimitive(fibPrimitiveRef.current);
         fibPrimitiveRef.current = null;
       }
+      if (buildSlicesPrimitiveRef.current) {
+        volumeSeries.detachPrimitive(buildSlicesPrimitiveRef.current);
+        buildSlicesPrimitiveRef.current = null;
+      }
       chart.remove();
       chartRef.current = null;
       seriesRef.current = {};
@@ -588,7 +889,7 @@ export default function TradingChart({
 
   useEffect(() => {
     const s = seriesRef.current;
-    if (!s.candles || !s.volume || !s.build) return;
+    if (!s.candles || !s.volume || !s.buildHover) return;
     s.candles.setData(candleData);
     s.volume.setData(volumeData);
     s.oracle?.setData(oracleData);
@@ -598,34 +899,18 @@ export default function TradingChart({
     s.bbLower?.setData(bbLower);
     s.bbMid?.setData(bbMid);
 
-    s.build.applyOptions({ visible: showBuild });
-    if (!showBuild) {
-      buildSamplesRef.current.clear();
-      buildKeyRef.current = seriesKey;
-      lastBuildCandleStartRef.current = null;
-      s.build.setData([]);
-    }
-
-    if (buildKeyRef.current !== seriesKey) {
-      buildSamplesRef.current.clear();
-      buildKeyRef.current = seriesKey;
-      lastBuildCandleStartRef.current = null;
-    }
-
-    if (!showBuild) {
-      s.sma20?.applyOptions({ visible: showIndicators });
-      s.ema20?.applyOptions({ visible: showIndicators });
-      s.bbUpper?.applyOptions({ visible: showIndicators });
-      s.bbLower?.applyOptions({ visible: showIndicators });
-      s.bbMid?.applyOptions({ visible: showIndicators });
-      return;
-    }
-
     const bs = resolveBucketSeconds(bucketSeconds, candles);
     const eps = 1e-3;
     const maxPointsPerCandle = 600;
     const minStep = Math.max(0.5, bs / maxPointsPerCandle);
     const map = buildSamplesRef.current;
+
+    if (buildKeyRef.current !== seriesKey) {
+      map.clear();
+      buildKeyRef.current = seriesKey;
+      lastBuildCandleStartRef.current = null;
+    }
+
     const visibleStarts = new Set(candles.map((c) => c.time));
     for (const start of Array.from(map.keys())) {
       if (!visibleStarts.has(start)) map.delete(start);
@@ -671,63 +956,27 @@ export default function TradingChart({
       lastBuildCandleStartRef.current = start;
     }
 
-    const buildRaw: LinePoint[] = [];
-    for (const c of candles) {
-      const list = map.get(c.time);
-      if (!list?.length) continue;
+    const buildPrimitive = buildSlicesPrimitiveRef.current;
+    buildPrimitive?.setData({ candles, bucketSeconds: bs, samples: map });
+    buildPrimitive?.setEnabled(!showBuild);
 
-      const startT = c.time + eps;
-      const endT = c.time + bs - eps;
-      if (!(endT > startT)) continue;
+    if (showBuild) {
+      const hoverTime = hoverCandleTime;
+      const hoverCandle = hoverTime == null ? null : candles.find((c) => c.time === hoverTime);
+      const hoverData = hoverCandle ? buildDeltaSeriesForCandle(hoverCandle, bs, map.get(hoverCandle.time)) : [];
 
-      buildRaw.push({ time: toTime(c.time) } as WhitespaceData);
-      buildRaw.push({ time: toTime(startT), value: 0 } as LineData);
-
-      let lastT = startT;
-      for (const p of list) {
-        let t = p.t;
-        if (t <= lastT + eps) t = lastT + eps;
-        if (t >= endT) break;
-        buildRaw.push({ time: toTime(t), value: p.v } as LineData);
-        lastT = t;
-      }
-
-      const finalDelta = c.close - c.open;
-      if (endT > lastT + eps) {
-        buildRaw.push({ time: toTime(endT), value: finalDelta } as LineData);
-      } else if (buildRaw.length) {
-        const prev = buildRaw[buildRaw.length - 1];
-        if ('value' in prev) {
-          buildRaw[buildRaw.length - 1] = { ...prev, value: finalDelta } as LineData;
-        }
+      if (hoverData.length) {
+        s.buildHover.applyOptions({ visible: true });
+        s.buildHover.setData(hoverData);
+      } else {
+        s.buildHover.applyOptions({ visible: false });
+        s.buildHover.setData([]);
       }
+    } else {
+      s.buildHover.applyOptions({ visible: false });
+      s.buildHover.setData([]);
     }
 
-    const buildColored: LinePoint[] = [];
-    let lastLineIdx: number | null = null;
-    let lastLineVal: number | null = null;
-    for (const p of buildRaw) {
-      if (!('value' in p)) {
-        buildColored.push(p);
-        lastLineIdx = null;
-        lastLineVal = null;
-        continue;
-      }
-
-      if (lastLineIdx != null && lastLineVal != null) {
-        const delta = p.value - lastLineVal;
-        const color = delta > 0 ? '#22c55e' : delta < 0 ? '#ef4444' : '#60a5fa';
-        const prev = buildColored[lastLineIdx] as LineData;
-        buildColored[lastLineIdx] = { ...prev, color };
-      }
-
-      buildColored.push({ time: p.time, value: p.value } as LineData);
-      lastLineIdx = buildColored.length - 1;
-      lastLineVal = p.value;
-    }
-
-    s.build.setData(buildColored);
-
     s.sma20?.applyOptions({ visible: showIndicators });
     s.ema20?.applyOptions({ visible: showIndicators });
     s.bbUpper?.applyOptions({ visible: showIndicators });
@@ -747,13 +996,14 @@ export default function TradingChart({
     candles,
     bucketSeconds,
     seriesKey,
+    hoverCandleTime,
   ]);
 
   useEffect(() => {
     const s = seriesRef.current;
     if (!s.candles) return;
     s.candles.applyOptions({ priceFormat });
-    s.build?.applyOptions({ priceFormat });
+    s.buildHover?.applyOptions({ priceFormat });
     s.oracle?.applyOptions({ priceFormat });
     s.sma20?.applyOptions({ priceFormat });
     s.ema20?.applyOptions({ priceFormat });
diff --git a/apps/visualizer/src/features/market/useDlobStats.ts b/apps/visualizer/src/features/market/useDlobStats.ts
new file mode 100644
index 0000000..0611e53
--- /dev/null
+++ b/apps/visualizer/src/features/market/useDlobStats.ts
@@ -0,0 +1,104 @@
+import { useEffect, useMemo, useState } from 'react';
+import { subscribeGraphqlWs } from '../../lib/graphqlWs';
+
+export type DlobStats = {
+  marketName: string;
+  bestBid: number | null;
+  bestAsk: number | null;
+  mid: number | null;
+  spreadAbs: number | null;
+  spreadBps: number | null;
+  depthBidUsd: number | null;
+  depthAskUsd: number | null;
+  updatedAt: string | null;
+};
+
+function toNum(v: unknown): number | null {
+  if (v == null) return null;
+  if (typeof v === 'number') return Number.isFinite(v) ? v : null;
+  if (typeof v === 'string') {
+    const s = v.trim();
+    if (!s) return null;
+    const n = Number(s);
+    return Number.isFinite(n) ? n : null;
+  }
+  return null;
+}
+
+type HasuraDlobStatsRow = {
+  market_name: string;
+  best_bid_price?: string | null;
+  best_ask_price?: string | null;
+  mid_price?: string | null;
+  spread_abs?: string | null;
+  spread_bps?: string | null;
+  depth_bid_usd?: string | null;
+  depth_ask_usd?: string | null;
+  updated_at?: string | null;
+};
+
+type SubscriptionData = {
+  dlob_stats_latest: HasuraDlobStatsRow[];
+};
+
+export function useDlobStats(marketName: string): { stats: DlobStats | null; connected: boolean; error: string | null } {
+  const [stats, setStats] = useState<DlobStats | null>(null);
+  const [connected, setConnected] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const normalizedMarket = useMemo(() => (marketName || '').trim(), [marketName]);
+
+  useEffect(() => {
+    if (!normalizedMarket) {
+      setStats(null);
+      setError(null);
+      setConnected(false);
+      return;
+    }
+
+    setError(null);
+
+    const query = `
+      subscription DlobStats($market: String!) {
+        dlob_stats_latest(where: {market_name: {_eq: $market}}, limit: 1) {
+          market_name
+          best_bid_price
+          best_ask_price
+          mid_price
+          spread_abs
+          spread_bps
+          depth_bid_usd
+          depth_ask_usd
+          updated_at
+        }
+      }
+    `;
+
+    const sub = subscribeGraphqlWs<SubscriptionData>({
+      query,
+      variables: { market: normalizedMarket },
+      onStatus: ({ connected }) => setConnected(connected),
+      onError: (e) => setError(e),
+      onData: (data) => {
+        const row = data?.dlob_stats_latest?.[0];
+        if (!row?.market_name) return;
+        setStats({
+          marketName: row.market_name,
+          bestBid: toNum(row.best_bid_price),
+          bestAsk: toNum(row.best_ask_price),
+          mid: toNum(row.mid_price),
+          spreadAbs: toNum(row.spread_abs),
+          spreadBps: toNum(row.spread_bps),
+          depthBidUsd: toNum(row.depth_bid_usd),
+          depthAskUsd: toNum(row.depth_ask_usd),
+          updatedAt: row.updated_at ?? null,
+        });
+      },
+    });
+
+    return () => sub.unsubscribe();
+  }, [normalizedMarket]);
+
+  return { stats, connected, error };
+}
+
diff --git a/apps/visualizer/src/lib/graphqlWs.ts b/apps/visualizer/src/lib/graphqlWs.ts
new file mode 100644
index 0000000..36be894
--- /dev/null
+++ b/apps/visualizer/src/lib/graphqlWs.ts
@@ -0,0 +1,173 @@
+type HeadersMap = Record<string, string>;
+
+type SubscribeParams<T> = {
+  query: string;
+  variables?: Record<string, unknown>;
+  onData: (data: T) => void;
+  onError?: (err: string) => void;
+  onStatus?: (s: { connected: boolean }) => void;
+};
+
+function envString(name: string): string | undefined {
+  const v = (import.meta as any).env?.[name];
+  const s = v == null ? '' : String(v).trim();
+  return s ? s : undefined;
+}
+
+function resolveGraphqlHttpUrl(): string {
+  return envString('VITE_HASURA_URL') || '/graphql';
+}
+
+function resolveGraphqlWsUrl(): string {
+  const explicit = envString('VITE_HASURA_WS_URL');
+  if (explicit) return explicit;
+
+  const httpUrl = resolveGraphqlHttpUrl();
+  if (httpUrl.startsWith('ws://') || httpUrl.startsWith('wss://')) return httpUrl;
+  if (httpUrl.startsWith('http://')) return `ws://${httpUrl.slice('http://'.length)}`;
+  if (httpUrl.startsWith('https://')) return `wss://${httpUrl.slice('https://'.length)}`;
+
+  const proto = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
+  const host = window.location.host;
+  const path = httpUrl.startsWith('/') ? httpUrl : `/${httpUrl}`;
+  return `${proto}//${host}${path}`;
+}
+
+function resolveAuthHeaders(): HeadersMap | undefined {
+  const token = envString('VITE_HASURA_AUTH_TOKEN');
+  if (token) return { authorization: `Bearer ${token}` };
+  const secret = envString('VITE_HASURA_ADMIN_SECRET');
+  if (secret) return { 'x-hasura-admin-secret': secret };
+  return undefined;
+}
+
+type WsMessage =
+  | { type: 'connection_ack' | 'ka' | 'complete' }
+  | { type: 'connection_error'; payload?: any }
+  | { type: 'data'; id: string; payload: { data?: any; errors?: Array<{ message: string }> } }
+  | { type: 'error'; id: string; payload?: any };
+
+export type SubscriptionHandle = {
+  unsubscribe: () => void;
+};
+
+export function subscribeGraphqlWs<T>({ query, variables, onData, onError, onStatus }: SubscribeParams<T>): SubscriptionHandle {
+  const wsUrl = resolveGraphqlWsUrl();
+  const headers = resolveAuthHeaders();
+  let ws: WebSocket | null = null;
+  let closed = false;
+  let started = false;
+  let reconnectTimer: number | null = null;
+
+  const subId = '1';
+
+  const emitError = (e: unknown) => {
+    const msg = typeof e === 'string' ? e : String((e as any)?.message || e);
+    onError?.(msg);
+  };
+
+  const setConnected = (connected: boolean) => onStatus?.({ connected });
+
+  const start = () => {
+    if (!ws || started) return;
+    started = true;
+    ws.send(
+      JSON.stringify({
+        id: subId,
+        type: 'start',
+        payload: { query, variables: variables ?? {} },
+      })
+    );
+  };
+
+  const connect = () => {
+    if (closed) return;
+    started = false;
+    try {
+      ws = new WebSocket(wsUrl, 'graphql-ws');
+    } catch (e) {
+      emitError(e);
+      reconnectTimer = window.setTimeout(connect, 1000);
+      return;
+    }
+
+    ws.onopen = () => {
+      setConnected(true);
+      const payload = headers ? { headers } : {};
+      ws?.send(JSON.stringify({ type: 'connection_init', payload }));
+    };
+
+    ws.onmessage = (ev) => {
+      let msg: WsMessage;
+      try {
+        msg = JSON.parse(String(ev.data));
+      } catch (e) {
+        emitError(e);
+        return;
+      }
+
+      if (msg.type === 'connection_ack') {
+        start();
+        return;
+      }
+
+      if (msg.type === 'connection_error') {
+        emitError(msg.payload || 'connection_error');
+        return;
+      }
+
+      if (msg.type === 'ka' || msg.type === 'complete') return;
+
+      if (msg.type === 'error') {
+        emitError(msg.payload || 'subscription_error');
+        return;
+      }
+
+      if (msg.type === 'data') {
+        const errors = msg.payload?.errors;
+        if (Array.isArray(errors) && errors.length) {
+          emitError(errors.map((e) => e.message).join(' | '));
+          return;
+        }
+        if (msg.payload?.data != null) onData(msg.payload.data as T);
+      }
+    };
+
+    ws.onerror = () => {
+      setConnected(false);
+    };
+
+    ws.onclose = () => {
+      setConnected(false);
+      if (closed) return;
+      reconnectTimer = window.setTimeout(connect, 1000);
+    };
+  };
+
+  connect();
+
+  return {
+    unsubscribe: () => {
+      closed = true;
+      setConnected(false);
+      if (reconnectTimer != null) {
+        window.clearTimeout(reconnectTimer);
+        reconnectTimer = null;
+      }
+      if (!ws) return;
+      try {
+        ws.send(JSON.stringify({ id: subId, type: 'stop' }));
+        ws.send(JSON.stringify({ type: 'connection_terminate' }));
+      } catch {
+        // ignore
+      }
+      try {
+        ws.close();
+      } catch {
+        // ignore
+      }
+      ws = null;
+    },
+  };
+}
+
diff --git a/apps/visualizer/vite.config.ts b/apps/visualizer/vite.config.ts
index 6cbf362..9b42296 100644
--- a/apps/visualizer/vite.config.ts
+++ b/apps/visualizer/vite.config.ts
@@ -98,6 +98,8 @@ const uiProxyTarget =
   inferUiProxyTarget(apiProxyTarget) ||
   (apiProxyTargetUrl && apiProxyTargetPath === '/' ? stripTrailingSlashes(apiProxyTargetUrl.toString()) : undefined);
 
+const graphqlProxyTarget = process.env.GRAPHQL_PROXY_TARGET || process.env.HASURA_PROXY_TARGET || uiProxyTarget;
+
 function applyProxyBasicAuth(proxyReq: any) {
   if (!proxyBasicAuth) return false;
   const b64 = Buffer.from(`${proxyBasicAuth.username}:${proxyBasicAuth.password}`, 'utf8').toString('base64');
@@ -131,6 +133,24 @@ const proxy: Record<string, any> = {
   },
 };
 
+if (graphqlProxyTarget) {
+  for (const prefix of ['/graphql', '/graphql-ws']) {
+    proxy[prefix] = {
+      target: graphqlProxyTarget,
+      changeOrigin: true,
+      ws: true,
+      configure: (p: any) => {
+        p.on('proxyReq', (proxyReq: any) => {
+          applyProxyBasicAuth(proxyReq);
+        });
+        p.on('proxyReqWs', (proxyReq: any) => {
+          applyProxyBasicAuth(proxyReq);
+        });
+      },
+    };
+  }
+}
+
 if (uiProxyTarget) {
   for (const prefix of ['/whoami', '/auth', '/logout']) {
     proxy[prefix] = {
diff --git a/doc/workflow.md b/doc/workflow.md
index f43f09b..f180354 100644
--- a/doc/workflow.md
+++ b/doc/workflow.md
@@ -77,6 +77,7 @@ docker compose -f devops/app/docker-compose.yml --profile ingest up -d --build
 Jeśli chcesz szybko iterować nad UI bez deploya, możesz odpalić lokalny Vite i podpiąć go do backendu na VPS przez istniejący proxy `/api` na `trade.mpabi.pl`.
 
 - Vite trzyma `VITE_API_URL=/api` (default) i proxy’uje `/api/*` do VPS.
+- UI ma też GraphQL (Hasura) pod `/graphql` (HTTP + WS subscriptions) – w dev proxy’ujemy `/graphql` i `/graphql-ws` do VPS, żeby subscriptions działały na `http://localhost:5173`.
 - Auth w staging jest w trybie `session` (`/auth/login`, cookie `trade_session`), więc w dev proxy’ujemy też `/whoami`, `/auth/*`, `/logout`.
 - Dev proxy usuwa `Secure` z `Set-Cookie`, żeby cookie działało na `http://localhost:5173`.
 - Na VPS `trade-frontend` proxy’uje dalej do `trade-api` i wstrzykuje read-token **server-side** (token nie trafia do przeglądarki).
@@ -85,7 +86,7 @@ Przykład:
 
 ```bash
 cd apps/visualizer
-API_PROXY_TARGET=https://trade.mpabi.pl \
+API_PROXY_TARGET=https://trade.mpabi.pl GRAPHQL_PROXY_TARGET=https://trade.mpabi.pl \
 npm run dev
 ```
 
diff --git a/services/frontend/server.mjs b/services/frontend/server.mjs
index d336904..a74c0db 100644
--- a/services/frontend/server.mjs
+++ b/services/frontend/server.mjs
@@ -3,7 +3,9 @@ import { spawnSync } from 'node:child_process';
 import fs from 'node:fs';
 import http from 'node:http';
 import https from 'node:https';
+import net from 'node:net';
 import path from 'node:path';
+import tls from 'node:tls';
 
 const PORT = Number.parseInt(process.env.PORT || '8081', 10);
 if (!Number.isInteger(PORT) || PORT <= 0) throw new Error(`Invalid PORT: ${process.env.PORT}`);
@@ -16,6 +18,9 @@ const STATIC_DIR = process.env.STATIC_DIR || '/srv';
 const BASIC_AUTH_FILE = process.env.BASIC_AUTH_FILE || '/tokens/frontend.json';
 const API_READ_TOKEN_FILE = process.env.API_READ_TOKEN_FILE || '/tokens/read.json';
 const API_UPSTREAM = process.env.API_UPSTREAM || process.env.API_URL || 'http://api:8787';
+const HASURA_UPSTREAM = process.env.HASURA_UPSTREAM || 'http://hasura:8080';
+const HASURA_GRAPHQL_PATH = process.env.HASURA_GRAPHQL_PATH || '/v1/graphql';
+const GRAPHQL_CORS_ORIGIN = process.env.GRAPHQL_CORS_ORIGIN || process.env.CORS_ORIGIN || '*';
 const BASIC_AUTH_MODE = String(process.env.BASIC_AUTH_MODE || 'on')
   .trim()
   .toLowerCase();
@@ -413,6 +418,122 @@ function proxyApi(req, res, apiReadToken) {
   req.pipe(upstreamReq);
 }
 
+function withCors(res) {
+  res.setHeader('access-control-allow-origin', GRAPHQL_CORS_ORIGIN);
+  res.setHeader('access-control-allow-methods', 'GET,POST,OPTIONS');
+  res.setHeader(
+    'access-control-allow-headers',
+    'content-type, authorization, x-hasura-admin-secret, x-hasura-role, x-hasura-user-id'
+  );
+}
+
+function proxyGraphqlHttp(req, res) {
+  const upstreamBase = new URL(HASURA_UPSTREAM);
+  const inUrl = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
+
+  const target = new URL(upstreamBase.toString());
+  target.pathname = HASURA_GRAPHQL_PATH;
+  target.search = inUrl.search;
+
+  const isHttps = target.protocol === 'https:';
+  const lib = isHttps ? https : http;
+
+  const headers = stripHopByHopHeaders(req.headers);
+  headers.host = target.host;
+
+  const upstreamReq = lib.request(
+    {
+      protocol: target.protocol,
+      hostname: target.hostname,
+      port: target.port || (isHttps ? 443 : 80),
+      method: req.method,
+      path: target.pathname + target.search,
+      headers,
+    },
+    (upstreamRes) => {
+      const outHeaders = stripHopByHopHeaders(upstreamRes.headers);
+      withCors(res);
+      res.writeHead(upstreamRes.statusCode || 502, outHeaders);
+      upstreamRes.pipe(res);
+    }
+  );
+
+  upstreamReq.on('error', (err) => {
+    if (!res.headersSent) {
+      withCors(res);
+      send(res, 502, { 'content-type': 'text/plain; charset=utf-8' }, `bad_gateway: ${err?.message || err}`);
+    } else {
+      res.destroy();
+    }
+  });
+
+  req.pipe(upstreamReq);
+}
+
+function isGraphqlPath(pathname) {
+  return pathname === '/graphql' || pathname === '/graphql-ws';
+}
+
+function proxyGraphqlWs(req, socket, head) {
+  const upstreamBase = new URL(HASURA_UPSTREAM);
+  const inUrl = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
+
+  const target = new URL(upstreamBase.toString());
+  target.pathname = HASURA_GRAPHQL_PATH;
+  target.search = inUrl.search;
+
+  const port = Number(target.port || (target.protocol === 'https:' ? 443 : 80));
+  const host = target.hostname;
+
+  const connect =
+    target.protocol === 'https:'
+      ? () => tls.connect({ host, port, servername: host })
+      : () => net.connect({ host, port });
+
+  const upstream = connect();
+  upstream.setNoDelay(true);
+  socket.setNoDelay(true);
+
+  // For WebSocket upgrades we must forward `connection`/`upgrade` and related headers.
+  const headers = { ...req.headers };
+  delete headers['content-length'];
+  delete headers['content-type'];
+  headers.host = target.host;
+
+  const lines = [];
+  lines.push(`GET ${target.pathname + target.search} HTTP/1.1`);
+  for (const [k, v] of Object.entries(headers)) {
+    if (v == null) continue;
+    if (Array.isArray(v)) {
+      for (const vv of v) lines.push(`${k}: ${vv}`);
+    } else {
+      lines.push(`${k}: ${v}`);
+    }
+  }
+  lines.push('', '');
+  upstream.write(lines.join('\r\n'));
+
+  if (head?.length) upstream.write(head);
+
+  upstream.on('error', () => {
+    try {
+      socket.destroy();
+    } catch {
+      // ignore
+    }
+  });
+  socket.on('error', () => {
+    try {
+      upstream.destroy();
+    } catch {
+      // ignore
+    }
+  });
+
+  upstream.pipe(socket);
+  socket.pipe(upstream);
+}
+
 async function handler(req, res) {
   if (req.method === 'GET' && (req.url === '/healthz' || req.url?.startsWith('/healthz?'))) {
     send(
@@ -425,6 +546,25 @@ async function handler(req, res) {
   }
 
   const url = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
+  if (isGraphqlPath(url.pathname)) {
+    if (req.method === 'OPTIONS') {
+      withCors(res);
+      res.statusCode = 204;
+      res.end();
+      return;
+    }
+    if (AUTH_MODE !== 'off' && AUTH_MODE !== 'none' && AUTH_MODE !== 'disabled') {
+      const user = resolveAuthenticatedUser(req);
+      if (!user) {
+        withCors(res);
+        unauthorized(res);
+        return;
+      }
+    }
+    withCors(res);
+    proxyGraphqlHttp(req, res);
+    return;
+  }
   if (req.method === 'GET' && url.pathname === '/whoami') {
     sendJson(res, 200, { ok: true, user: resolveAuthenticatedUser(req), mode: AUTH_MODE });
     return;
@@ -532,6 +672,30 @@ const server = http.createServer((req, res) => {
     send(res, 500, { 'content-type': 'text/plain; charset=utf-8' }, String(e?.message || e));
   });
 });
+server.on('upgrade', (req, socket, head) => {
+  try {
+    const url = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
+    if (!isGraphqlPath(url.pathname)) {
+      socket.destroy();
+      return;
+    }
+    if (AUTH_MODE !== 'off' && AUTH_MODE !== 'none' && AUTH_MODE !== 'disabled') {
+      const user = resolveAuthenticatedUser(req);
+      if (!user) {
+        try {
+          socket.write('HTTP/1.1 401 Unauthorized\r\n\r\n');
+        } catch {
+          // ignore
+        }
+        socket.destroy();
+        return;
+      }
+    }
+    proxyGraphqlWs(req, socket, head);
+  } catch {
+    socket.destroy();
+  }
+});
 server.listen(PORT, () => {
   console.log(
     JSON.stringify(
@@ -540,6 +704,7 @@ server.listen(PORT, () => {
         port: PORT,
         staticDir: STATIC_DIR,
         apiUpstream: API_UPSTREAM,
+        hasuraUpstream: HASURA_UPSTREAM,
         basicAuthFile: BASIC_AUTH_FILE,
         basicAuthMode: BASIC_AUTH_MODE,
         apiReadTokenFile: API_READ_TOKEN_FILE,