catch a falling knife

catch a falling knife (third-person singular simple present catches a falling knife, present participle catching a falling knife, simple past and past participle caught a falling knife)

1. (trading) To buy an instrument whose price is falling rapidly.

   Buying that stock now would be catching a falling knife. Wait until you see capitulation.

2. (trading) To buy an instrument with the unconfirmed assumption that price will reverse.