diff --git a/src/pages/stock/Stock.css b/src/pages/stock/Stock.css
index 35c4686..88f6944 100644
--- a/src/pages/stock/Stock.css
+++ b/src/pages/stock/Stock.css
@@ -3349,4 +3349,5 @@
 }
 .wl-cond { font-size: 13px; font-weight: 600; }
 .wl-alert__price { font-size: 13px; color: var(--muted); }
+.wl-alert__reason { font-size: 12.5px; line-height: 1.45; color: #cbd5e1; }
 .wl-alert__detail { font-size: 12px; color: var(--muted); }
diff --git a/src/pages/stock/components/WatchlistTab.jsx b/src/pages/stock/components/WatchlistTab.jsx
index e762597..aaf496c 100644
--- a/src/pages/stock/components/WatchlistTab.jsx
+++ b/src/pages/stock/components/WatchlistTab.jsx
@@ -24,6 +24,7 @@ const AlertCard = ({ a }) => {
         <span className="wl-cond">{conditionLabel(a.condition)}</span>
         {a.price != null && <span className="wl-alert__price">{formatNumber(a.price)}원</span>}
       </div>
+      {a.reason && <div className="wl-alert__reason">{a.reason}</div>}
       {detailText && <div className="wl-alert__detail">{detailText}</div>}
     </div>
   );
diff --git a/src/pages/stock/components/WatchlistTab.test.jsx b/src/pages/stock/components/WatchlistTab.test.jsx
index a99ddf3..efc2d93 100644
--- a/src/pages/stock/components/WatchlistTab.test.jsx
+++ b/src/pages/stock/components/WatchlistTab.test.jsx
@@ -44,4 +44,19 @@ describe('WatchlistTab', () => {
     // 객체 detail이 문자열로 안전 렌더됨 (severity 값 노출)
     expect(screen.getByText(/normal/)).toBeInTheDocument();
   });
+
+  it('alert.reason(근거 문자열)을 condition 라벨과 함께 렌더', () => {
+    const wl = {
+      ...baseWl,
+      alerts: [{
+        id: 40, ticker: '000660', name: 'SK하이닉스', kind: 'sell', condition: 'sell_ma_break',
+        price: 2120000, detail: { ma50: 2123160, ma200: null, severity: 'normal' },
+        fired_at: '2026-07-09T02:55:00Z',
+        reason: '주요 이평선(MA50/200) 이탈 — 추세 훼손, 보유 재검토',
+      }],
+    };
+    render(<WatchlistTab wl={wl} />);
+    expect(screen.getByText('주요 이평선(MA50/200) 이탈 — 추세 훼손, 보유 재검토')).toBeInTheDocument();
+    expect(screen.getByText('이평선 이탈')).toBeInTheDocument();
+  });
 });