diff --git a/stock-lab/app/screener/router.py b/stock-lab/app/screener/router.py
index aadd10f..bbf6905 100644
--- a/stock-lab/app/screener/router.py
+++ b/stock-lab/app/screener/router.py
@@ -45,7 +45,12 @@ def _db_path() -> str:
 
 
 def _conn() -> sqlite3.Connection:
-    return sqlite3.connect(_db_path())
+    # WAL 모드 + busy_timeout으로 동시 read/write lock 회피
+    # (snapshot/refresh 직후 /run이 SELECT 시 OperationalError 'database is locked' 방지)
+    conn = sqlite3.connect(_db_path(), timeout=30.0)
+    conn.execute("PRAGMA journal_mode=WAL")
+    conn.execute("PRAGMA busy_timeout=30000")
+    return conn
 
 
 # ---------- /nodes ----------