Pre-earnings straddle/strangle

[mynd66]

Quote from livevol_ophir:

What I was saying is that these guys don't do any direction bets. They find the ones that tend (overwhelmingly) to be front spreads (i.e. sales). Direction neutral, short vega. There are a bunch, but it takes a while to find 'em.

Successful option traders tend to have very similar PnL trends. Make money most days small (ish) and then every once in a while a biggish loser.

So do the pros build charts similar to the ones on your blog to find potential setups or do they use statistical data to find the likely direction of vega during earnings? I mean from what your saying they are just looking to short vega. Wouldn't that mean checking historical data to find likely setups?