diff --git a/strategy_lab.py b/strategy_lab.py
index b52e321c..0cf35511 100644
--- a/strategy_lab.py
+++ b/strategy_lab.py
@@ -681,36 +681,39 @@ def _get_external_factors(code, dt):
         return _EXTERNAL_CACHE[key]
     result = {}
     try:
+        import sqlite3
+        _conn = sqlite3.connect(DB_PATH)
         # 行业动量 sec_ret20（sector_index_daily 20日涨跌）
-        _srow = conn.execute("SELECT sector_name FROM stock_sectors WHERE code=? LIMIT 1", (code,)).fetchone()
+        _srow = _conn.execute("SELECT sector_name FROM stock_sectors WHERE code=? LIMIT 1", (code,)).fetchone()
         if _srow and _srow[0]:
             _sector = _srow[0]
-            _prev = conn.execute(
+            _prev = _conn.execute(
                 "SELECT close FROM sector_index_daily WHERE sector=? AND date<=? ORDER BY date DESC LIMIT 21",
                 (_sector, dt)).fetchall()
             if len(_prev) >= 20 and _prev[-1][0] and _prev[-1][0] > 0:
                 result['sec_ret20'] = round((_prev[0][0] - _prev[-1][0]) / _prev[-1][0] * 100, 2)
         # 新闻 3 日计数 news3
-        _nrow = conn.execute(
+        _nrow = _conn.execute(
             "SELECT COUNT(*) FROM stock_news WHERE code=? AND date>? AND date<=?",
             (code, _days_ago(dt, 3), dt)).fetchone()
         if _nrow:
             result['news3'] = _nrow[0]
         # 基本面分位 mcap_q/pe_q
-        _frow = conn.execute(
+        _frow = _conn.execute(
             "SELECT mcap_total, pe FROM stock_fundamentals WHERE code=?", (code,)).fetchone()
         if _frow and _frow[0]:
             _mcap = _frow[0]
-            _t = conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE mcap_total>0 AND mcap_total<?", (_mcap,)).fetchone()[0]
-            _tot = conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE mcap_total>0").fetchone()[0]
+            _t = _conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE mcap_total>0 AND mcap_total<?", (_mcap,)).fetchone()[0]
+            _tot = _conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE mcap_total>0").fetchone()[0]
             if _tot:
                 result['mcap_q'] = round(_t / _tot, 3)
         if _frow and _frow[1]:
             _pe = _frow[1]
-            _t = conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE pe>0 AND pe<?", (_pe,)).fetchone()[0]
-            _tot = conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE pe>0").fetchone()[0]
+            _t = _conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE pe>0 AND pe<?", (_pe,)).fetchone()[0]
+            _tot = _conn.execute("SELECT COUNT(*) FROM stock_fundamentals WHERE pe>0").fetchone()[0]
             if _tot:
                 result['pe_q'] = round(_t / _tot, 3)
+        _conn.close()
     except Exception:
         pass
     _EXTERNAL_CACHE[key] = result
@@ -744,6 +747,16 @@ def prepare_sector_context(start_date, end_date):
                 sec_hl[sec].append((d, row[4], row[5]))
         for sec, series in by_sector.items():
             closes = [c for _, c, _ in series]
+            # 2026-08-11 性能修复：ADX 全序列只算一次（原代码内层每天重算=O(N²)，296板块×490天卡死）
+            from backtest_framework import calc_trend_strength
+            _hl = sec_hl.get(sec, [])
+            _av = None
+            if len(_hl) >= 20:
+                _hs = [x[1] for x in _hl]
+                _ls = [x[2] for x in _hl]
+                _cs = [c for _, c, _ in series]
+                if len(_cs) == len(_hl):
+                    _av = calc_trend_strength(_hs, _ls, _cs, 14)
             for i, (d, close, chg) in enumerate(series):
                 above = slope = None
                 if i >= 19:
@@ -753,17 +766,7 @@ def prepare_sector_context(start_date, end_date):
                         ma20_5 = sum(closes[i-24:i-4]) / 20
                         if ma20_5 > 0:
                             slope = round((ma20 - ma20_5) / ma20_5 * 100, 3)
-                _adx = None
-                _hl = sec_hl.get(sec, [])
-                if len(_hl) >= 20 and i >= 14:
-                    from backtest_framework import calc_trend_strength
-                    _hs = [x[1] for x in _hl]
-                    _ls = [x[2] for x in _hl]
-                    _cs = [c for _, c, _ in series]
-                    if len(_cs) == len(_hl):
-                        _av = calc_trend_strength(_hs, _ls, _cs, 14)
-                        if i < len(_av):
-                            _adx = _av[i]
+                _adx = _av[i] if (_av is not None and i < len(_av)) else None
                 _SECTOR_CTX.setdefault(d, {})[sec] = {
                     'change': chg, 'above_ma20': above, 'slope': slope, 'adx': _adx,
                 }