[bluGill]

'Buy the rumor sell the news'. I'd expect most people to not know that advice but pros would. that is pros would know that before most major announcements people had alread guessed based on other indicators and so the announcement is priced in already.

if you could find an alien civialization with a stock market I'd expect pros to do similiarly well just based on that.

amature traders in the real world tend to be more in tune to rumors and thus more likely to get it right since they had already traded by this sime. (or so I would guess)