1. jump the gun - Verb
2. jump the gun - Phrase
(sports) To begin a race too soon, before the starting gun goes off.
(idiomatic) To act or begin too soon or without due caution.
(idiomatic, finance, investing) To trade securities based on information that is not yet public; to trade on inside information.
Source: en.wiktionary.orgAgain: Warner Bros. doesn’t care, and they won’t jump the gun and release on VOD early. Source: Internet
I'm going to totally jump the gun and guess this will turn out to be a conservative manly-man actually in charge of something important. Source: Internet
We recommend investors to preserve cash and not to jump the gun in this phony rally and wait for markets to correct. Source: Internet