Trades made with/without insider knowledge reveal the same amount of information to the market since the market doesn't know what made you decide to trade. It's

Trades made with/without insider knowledge reveal the same amount of information to the market since the market doesn't know what made you decide to trade. It's illegal for a few reasons - it encourages quid-pro-quo relationships between investors and businesses, makes the good investment opportunities only available to those with privileged relationships (and magnifies 'the rich get richer' problem), and poses serious conflict of interest problems to everybody involved.