Insider trading isn't illegal because it's unfair to retail investors--it's illegal because it's unfair to _existing shareholders_ , which is a much more defensible position.
Imagine you're an executive with inside information that you think will make the stock go up. So you buy some stock (from an existing shareholder, obviously), and then the stock goes up. That shareholder rightly will feel stiffed.
Conversely if you sell stock and it goes down, the person you sold it to--now a shareholder to whom you have a fiduciary responsibility--is left holding the bag.
Can you elaborate on what you'd consider fair? Or do you think it would be acceptable to allow trading on inside information in the current system?
The only fair system I can imagine (fairer than the status quo by my estimation) would be complete transparency updated on a continual basis. But I can imagine it would be difficult to keep that up while making productive business relationships.
Is it "fair" that quant hedge funds have hundreds of PhDs developing algorithms to trade the markets efficiently, or that fundamental hedge funds spend millions on research? While there are a few restrictions around insiders trading, it is very much not the case that fairness in the sense of everyone having equal access to all information is or should be the goal of financial regulation.
Matt Levine has written about this many times, here's one:
My point is that in the markets, like in sports, a "fair contest" does not mean that both parties are equally likely to be successful. "Fairness" means that the rules were followed. Right now a PhD with a model is allowed to use his information advantage if he's trading against someone less informed, but an insider to the company is not. It may be the case that insider trading laws as they currently exist are good and help financial markets work better, but if that's true it's not because no one with an information advantage should be allowed to trade.
For this reason I believe insider trading should be legal. It's already widespread and difficult/impossible to police. Keeping it illegal gives retail investors a false sense of security when in reality this is how the vast majority of hedge funds/sophisticated market players are making their money.
Imagine you're an executive with inside information that you think will make the stock go up. So you buy some stock (from an existing shareholder, obviously), and then the stock goes up. That shareholder rightly will feel stiffed.
Conversely if you sell stock and it goes down, the person you sold it to--now a shareholder to whom you have a fiduciary responsibility--is left holding the bag.