diff --git a/tools/init_performance_tables.py b/tools/init_performance_tables.py
new file mode 100644
index 0000000..da176e0
--- /dev/null
+++ b/tools/init_performance_tables.py
@@ -0,0 +1,87 @@
+#!/usr/bin/env python3
+"""
+performance, positions 테이블 초기 데이터 생성
+T+20 모니터링 활성화
+"""
+
+import sqlite3
+from pathlib import Path
+from datetime import datetime
+
+def init_performance_tables():
+    """초기 성과 데이터 생성"""
+
+    db_path = Path('src/quant_engine/snapshot_admin.db')
+    conn = sqlite3.connect(db_path)
+    cursor = conn.cursor()
+
+    # 1. performance 테이블에 샘플 거래 기록 추가
+    sample_trades = [
+        ('005930', 'Samsung Electronics', '2026-06-01', 70000, 100, 70000, 72000, 2.86, 'COMPLETED', 'T+20'),
+        ('000660', 'SK Hynix', '2026-06-05', 120000, 50, 120000, 121500, 1.25, 'ACTIVE', None),
+        ('035420', 'NAVER', '2026-06-10', 385000, 10, 385000, 390000, 1.30, 'COMPLETED', 'T+20'),
+    ]
+
+    print(f"performance 초기화: {len(sample_trades)}개 거래 추가")
+    for ticker, name, entry_date, entry_price, qty, _, current_price, pnl_pct, status, t20_milestone in sample_trades:
+        cursor.execute("""
+            INSERT INTO performance
+              (ticker, name, entry_date, entry_price, quantity, current_price, pnl_pct, status, t20_milestone)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+        """, (
+            ticker,
+            name,
+            entry_date,
+            entry_price,
+            qty,
+            current_price,
+            pnl_pct,
+            status,
+            t20_milestone
+        ))
+
+    # 2. positions 테이블에 현재 포지션 추가
+    sample_positions = [
+        ('005930', 'Samsung Electronics', 100, 70000, 72000, 70500, 'IT'),
+        ('000660', 'SK Hynix', 50, 120000, 121500, 120750, 'IT'),
+        ('035420', 'NAVER', 10, 385000, 390000, 387500, 'Internet'),
+    ]
+
+    print(f"positions 초기화: {len(sample_positions)}개 포지션 추가")
+
+    today = datetime.now().isoformat()
+    for ticker, name, quantity, entry_price, current_price, avg_cost, sector in sample_positions:
+        cursor.execute("""
+            INSERT INTO positions
+              (ticker, name, quantity, entry_price, current_price, average_cost, sector, updated_at)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?)
+        """, (
+            ticker,
+            name,
+            quantity,
+            entry_price,
+            current_price,
+            avg_cost,
+            sector,
+            today
+        ))
+
+    conn.commit()
+
+    # 검증
+    cursor.execute("SELECT COUNT(*) FROM performance")
+    perf_count = cursor.fetchone()[0]
+
+    cursor.execute("SELECT COUNT(*) FROM positions")
+    pos_count = cursor.fetchone()[0]
+
+    print(f"\n[결과]")
+    print(f"  performance: {perf_count}개 행")
+    print(f"  positions: {pos_count}개 행")
+
+    conn.close()
+
+    print(f"\n[OK] T+20 모니터링 초기화 완료")
+
+if __name__ == "__main__":
+    init_performance_tables()