Is there any solid research for positive or negative influences of earnings reports on stock prices?

Just curious, I've never traded off of a company just because of releasing a earnings report (usually do options on the SPY anyway) but see tons of info on it that seems to always contradict the last thing I read.

Submitted April 19, 2015 at 02:27AM by CosmicCouchPotato http://ift.tt/1EfN5kx