diff --git a/unit/stock_system/stock_system.ipynb b/unit/stock_system/stock_system.ipynb
index 0871453..38d7192 100644
--- a/unit/stock_system/stock_system.ipynb
+++ b/unit/stock_system/stock_system.ipynb
@@ -92,7 +92,7 @@
     "        # 以這個例子為例，用 1/4 買 1214；用 3/4 放空 2351\n",
     "        \"weight\": 1, \n",
     "\n",
-    "        # 以下三個條件其中一個成力就會賣出\n",
+    "        # 以下三個條件其中一個成立就會賣出\n",
     "        \"close_high_price\": 16.8, # 比這個價格高就賣\n",
     "        \"close_low_price\": 16.3 # 比這個價格低也賣(停損點)\n",
     "        \"life\": 5, # 如果以上兩個條件都沒發生，會在 5 天會以收盤價賣\n",