As Matt Levine likes to say, "Insider trading isn't about fairness, it's about theft".
Insider trading isn't about making the markets fair and giving the same information to all investors. It's about stopping people from trading on information they don't own - i.e. with information owned by the company itself.
If I fly a helicopter and see oil levels in BP's oil tanks, I can trade on that information just fine, even if I mighjt be the only person with that info. If BP calls me up and tells me what their oil levels are in the same tanks, I can't trade on that information, because it was obtained from the company.
Insider trading isn't about making the markets fair and giving the same information to all investors. It's about stopping people from trading on information they don't own - i.e. with information owned by the company itself.
If I fly a helicopter and see oil levels in BP's oil tanks, I can trade on that information just fine, even if I mighjt be the only person with that info. If BP calls me up and tells me what their oil levels are in the same tanks, I can't trade on that information, because it was obtained from the company.