deer in the headlights字面意思是聚光灯下的鹿，引申为不知所措、狭路相逢。

【例句】
Traders dream of profits but often freeze like deer in the headlights when a losing trade hits them.
交易者们梦想赢利，但是当亏损击中他们时，往往就不知所措了。

The video cameras caught subjects' facial expressions during the tests, ranging from deer in the headlights to seriously upset.
摄像机记录下了在测试过程中被试的面部表情，从漫不经心到极度沮丧都有。