> By definition, an efficient market has all the publicly known information already encoded in its prices. Hence, even theoretically it's impossible to beat the

> By definition, an efficient market has all the publicly known information already encoded in its prices. Hence, even theoretically it's impossible to beat the market without doing insider trading, which is considered illegal and hence "cheating". Umm, no. Illegal insider trading is defined as trading on information that is not yours. There is relevant non-public information that doesn't qualify as "not yours".