diff --git a/backend/app/fetch/fundamentals.py b/backend/app/fetch/fundamentals.py
index a2db16d..97f2e21 100644
--- a/backend/app/fetch/fundamentals.py
+++ b/backend/app/fetch/fundamentals.py
@@ -63,8 +63,10 @@ def _fetch_one(code: str, target: date) -> Fundamentals | None:
         try:
             cap_df = krx.get_market_cap(ds, ds, code)
             fund_df = krx.get_market_fundamental(ds, ds, code)
-        except Exception:  # noqa: BLE001
-            logger.exception("pykrx fundamentals failed code=%s date=%s", code, ds)
+        except Exception as exc:  # noqa: BLE001
+            # logger.exception 은 예전에 pykrx/KRX 비정상 응답 traceback 포매팅 중
+            # UnicodeDecodeError 로 API 500 을 만든 적이 있음 → %r 로 안전하게 직렬화.
+            logger.error("pykrx fundamentals failed code=%s date=%s err=%r", code, ds, exc)
             return None
 
         cap_ok = cap_df is not None and not cap_df.empty