diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..8a352df
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-07-19 - Fast Time-Series Lookups via Binary Search
+**Learning:** The `backtestRunner` loops repeatedly over historical time-series data. Previous logic used `.filter((b) => b.time <= asOf)` to get the price of a stock at a specific turn. This caused an $O(N)$ operation inside an already heavy simulation loop, leading to $O(T \times N)$ time complexity for $T$ turns.
+**Action:** Since time-series bar data (like `OHLCV`) is naturally sorted chronologically, use `findLastBarIndex` (binary search) to retrieve the required index in $O(\log N)$ time. I have added this reusable utility to `src/data/sources/dnsePublic.ts`. Prefer this utility over full array slicing/filtering for performance-critical lookups on time-sorted arrays.
diff --git a/package.json b/package.json
index dd2a5c4..6d0265e 100644
--- a/package.json
+++ b/package.json
@@ -76,6 +76,10 @@
     "vitest": "^2.1.3"
   },
   "pnpm": {
+    "overrides": {
+      "undici": ">=7.28.0 <8.0.0",
+      "ws": ">=8.21.0"
+    },
     "onlyBuiltDependencies": [
       "better-sqlite3"
     ]
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8e3f135..abb401c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -4,6 +4,10 @@ settings:
   autoInstallPeers: true
   excludeLinksFromLockfile: false
 
+overrides:
+  undici: '>=7.28.0 <8.0.0'
+  ws: '>=8.21.0'
+
 importers:
 
   .:
@@ -33,8 +37,8 @@ importers:
         specifier: ^3.1.0
         version: 3.1.0
       undici:
-        specifier: ^6.20.0
-        version: 6.25.0
+        specifier: '>=7.28.0 <8.0.0'
+        version: 7.28.0
       yaml:
         specifier: ^2.6.0
         version: 2.8.3
@@ -1516,12 +1520,8 @@ packages:
   undici-types@6.21.0:
     resolution: {integrity: sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==}
 
-  undici@6.25.0:
-    resolution: {integrity: sha512-ZgpWDC5gmNiuY9CnLVXEH8rl50xhRCuLNA97fAUnKi8RRuV4E6KG31pDTsLVUKnohJE0I3XDrTeEydAXRw47xg==}
-    engines: {node: '>=18.17'}
-
-  undici@7.25.0:
-    resolution: {integrity: sha512-xXnp4kTyor2Zq+J1FfPI6Eq3ew5h6Vl0F/8d9XU5zZQf1tX9s2Su1/3PiMmUANFULpmksxkClamIZcaUqryHsQ==}
+  undici@7.28.0:
+    resolution: {integrity: sha512-cRZYrTDwWznlnRiPjggAGxZXanty6M8RV1ff8Wm4LWXBp7/IG8v5DnOm74DtUBp9OONpK75YlPnIjQqX0dBDtA==}
     engines: {node: '>=20.18.1'}
 
   universalify@0.1.2:
@@ -1622,8 +1622,8 @@ packages:
   wrappy@1.0.2:
     resolution: {integrity: sha512-l4Sp/DRseor9wL6EvV2+TuQn63dMkPjZ/sp9XkghTEbV9KlPS1xUsZ3u7/IQO4wxtcFB4bgpQPRcR3QCvezPcQ==}
 
-  ws@8.20.0:
-    resolution: {integrity: sha512-sAt8BhgNbzCtgGbt2OxmpuryO63ZoDk/sqaB/znQm94T4fCEsy/yV+7CdC1kJhOU9lboAEU7R3kquuycDoibVA==}
+  ws@8.21.1:
+    resolution: {integrity: sha512-+0NTnW77fFN/DjQi6k/Sq/Yvk4Sgajw7urW8V+asjXnRgDs9gyGkdb7EzgfhA4goXsRIZKE28fzIXBHEzhuiWw==}
     engines: {node: '>=10.0.0'}
     peerDependencies:
       bufferutil: ^4.0.1
@@ -2281,7 +2281,7 @@ snapshots:
       parse5: 7.3.0
       parse5-htmlparser2-tree-adapter: 7.1.0
       parse5-parser-stream: 7.1.2
-      undici: 7.25.0
+      undici: 7.28.0
       whatwg-mimetype: 4.0.0
 
   chownr@1.1.4: {}
@@ -2590,7 +2590,7 @@ snapshots:
       type-fest: 4.41.0
       widest-line: 5.0.0
       wrap-ansi: 9.0.2
-      ws: 8.20.0
+      ws: 8.21.1
       yoga-layout: 3.2.1
     optionalDependencies:
       '@types/react': 18.3.28
@@ -2986,9 +2986,7 @@ snapshots:
 
   undici-types@6.21.0: {}
 
-  undici@6.25.0: {}
-
-  undici@7.25.0: {}
+  undici@7.28.0: {}
 
   universalify@0.1.2: {}
 
@@ -3083,7 +3081,7 @@ snapshots:
 
   wrappy@1.0.2: {}
 
-  ws@8.20.0: {}
+  ws@8.21.1: {}
 
   yaml@2.8.3: {}
 
diff --git a/src/agent/backtestRunner.ts b/src/agent/backtestRunner.ts
index e91de2c..4fbd0ae 100644
--- a/src/agent/backtestRunner.ts
+++ b/src/agent/backtestRunner.ts
@@ -2,7 +2,7 @@ import { randomUUID } from "node:crypto";
 import { loadConfig } from "../config/loader.js";
 import { getDb } from "../storage/db.js";
 import { getBacktestBroker } from "../broker/index.js";
-import { getStockOhlcv, getIndexOhlcv, type Bar } from "../data/sources/dnsePublic.js";
+import { getStockOhlcv, getIndexOhlcv, findLastBarIndex, type Bar } from "../data/sources/dnsePublic.js";
 import { DISCOVERY_UNIVERSE, discoverTickers } from "../tools/discover.js";
 import { setActiveAsOf } from "./clock.js";
 import { runTeamAnalysis } from "./team/index.js";
@@ -298,8 +298,8 @@ export async function runBacktestSession(
   );
 
   const vnindexAt = (asOf: number): number | null => {
-    const series = vnindex.filter((b) => b.time <= asOf);
-    return series.length ? series[series.length - 1]!.close : null;
+    const idx = findLastBarIndex(vnindex, asOf);
+    return idx !== -1 ? vnindex[idx]!.close : null;
   };
   const vnindexBaseline = vnindexAt(intervalTurns[0]!);
   if (vnindexBaseline == null) throw new Error(`no VNINDEX data at first ${interval.label} turn`);
@@ -312,8 +312,10 @@ export async function runBacktestSession(
       throwIfAborted(cb.signal);
       const dateIso = ictLabel(asOf);
       const priceOverride = (sym: string): number | null => {
-        const series = bars[sym]?.filter((b) => b.time <= asOf) ?? [];
-        return series.length ? series[series.length - 1]!.close : null;
+        const series = bars[sym];
+        if (!series || series.length === 0) return null;
+        const idx = findLastBarIndex(series, asOf);
+        return idx !== -1 ? series[idx]!.close : null;
       };
       broker.setPriceOverride(priceOverride);
       cb.onTurnStart?.({ asOf, dateIso });
diff --git a/src/data/sources/dnsePublic.ts b/src/data/sources/dnsePublic.ts
index 151733c..09038c4 100644
--- a/src/data/sources/dnsePublic.ts
+++ b/src/data/sources/dnsePublic.ts
@@ -24,6 +24,27 @@ export interface Bar {
   volume: number;
 }
 
+/**
+ * Finds the index of the last bar with time <= targetTime.
+ * Requires the bars array to be sorted chronologically by time.
+ * Returns -1 if no such bar exists.
+ */
+export function findLastBarIndex(bars: Bar[], targetTime: number): number {
+  let left = 0;
+  let right = bars.length - 1;
+  let ans = -1;
+  while (left <= right) {
+    const mid = Math.floor((left + right) / 2);
+    if (bars[mid]!.time <= targetTime) {
+      ans = mid;
+      left = mid + 1;
+    } else {
+      right = mid - 1;
+    }
+  }
+  return ans;
+}
+
 async function fetchOhlcs(
   kind: "stock" | "index",
   symbol: string,
@@ -68,7 +89,9 @@ function clipBars(bars: Bar[]): Bar[] {
     asOfClock.getStore()?.asOfSec != null || isAsOfOverridden();
   if (!hasOverride) return bars;
   const asOf = nowSec();
-  return bars.filter((b) => b.time <= asOf);
+  const idx = findLastBarIndex(bars, asOf);
+  if (idx === -1) return [];
+  return bars.slice(0, idx + 1);
 }
 
 export async function getStockOhlcv(