> Double blind? Consider e.g. knowledge the Fed is planning on raising interest rates before the public has it. That affects the market as a whole, so they could short sp500 and have a leg up on us regular folks.

No, that's not how that would work. You'd treat it the same way that you do with executives owning stock but having insider knowledge. All of their transfers are done on a schedule and changes to the schedule have to be done in advance.