Why be an option/futures/day trader when it is zero-sum?
greatreorx: "When you enter the game, you are assuming that you are better than at least half of the other players."I think the difference is - at what point does that assumption become atleast somewhat provable. Shaquille O'Neal was probably an athletic 6'10" 280 lbs in high school.  Just because the game of basketball itself is zero sum, does that make it irrational to think that he would become a decent professional basketball player?My favorite part of Taleb's book is when he describes the investing world as if all player's had a random 50/50 shot of making money each year.  There are millions of investors, by random chance thousands will do really well, a handful will do really, really well over the course of decades.  How do you know Warren Buffet is not part of that handful that is successful purely by chance?  It's been awhile since I've read the book, but I remember his philosophy being something like if you have a logical investing/hypothesis that gets proven results, then maybe we can say it's not by chance.So to answer your question, if you think you have an objective theory/algorithm/etc for option trading and have done blind historical tests or have successfully paper traded for a year+, then you might be on to something. If you think you are just smarter than everybody else, or maybe had a couple successful stock trades, it's probably not a good idea.