diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..989a6ff
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-14 - Time-Series O(log n) Search Pattern
+**Learning:** `src/agent/backtestRunner.ts` makes heavy use of `.filter((b) => b.time <= asOf)` to get the latest close price inside loop bounds, changing potentially O(1) loop lookups or O(log n) lookups into repetitive O(n) filtering over large arrays.
+**Action:** Expose `findLastBarIndex` in `src/data/sources/dnsePublic.ts` and use binary search or track indices explicitly in tight loops.
diff --git a/package.json b/package.json
index dd2a5c4..92516ea 100644
--- a/package.json
+++ b/package.json
@@ -78,7 +78,11 @@
   "pnpm": {
     "onlyBuiltDependencies": [
       "better-sqlite3"
-    ]
+    ],
+    "overrides": {
+      "undici": ">=7.28.0 <8.0.0",
+      "ws": ">=8.21.0"
+    }
   },
   "packageManager": "pnpm@10.33.2+sha512.a90faf6feeab71ad6c6e57f94e0fe1a12f5dcc22cd754db40ae9593eb6a3e0b6b12e3540218bb37ae083404b1f2ce6db2a4121e979829b4aff94b99f49da1cf8"
 }
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..610ee01 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 >= 0 ? 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 +312,9 @@ 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] ?? [];
+        const idx = findLastBarIndex(series, asOf);
+        return idx >= 0 ? 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..ee39639 100644
--- a/src/data/sources/dnsePublic.ts
+++ b/src/data/sources/dnsePublic.ts
@@ -61,6 +61,26 @@ export function seriesToBars(s: OhlcvSeries): Bar[] {
   return out;
 }
 
+/**
+ * O(log n) binary search to find the last bar index with time <= timeSec.
+ * Returns -1 if no such bar exists.
+ */
+export function findLastBarIndex(bars: Bar[], timeSec: number): number {
+  let low = 0;
+  let high = bars.length - 1;
+  let ans = -1;
+  while (low <= high) {
+    const mid = (low + high) >>> 1;
+    if (bars[mid]!.time <= timeSec) {
+      ans = mid;
+      low = mid + 1;
+    } else {
+      high = mid - 1;
+    }
+  }
+  return ans;
+}
+
 function clipBars(bars: Bar[]): Bar[] {
   // Clip when an as-of clock is active (ALS or module override). When neither
   // is set, fall through unchanged — DNSE only returns historical data anyway.