>I would prefer a public registry listing all congressional trades
Wouldn't your proposal obscure congressional trading as well, because they want to preserve their alpha by not publishing their trades?
Of course then you have problems where people with private information are incentivized to leak that information, which is bad for national security and other areas where secrecy is needed, but we already have laws protecting that information without adding insider trading to them.
It would need to be studied and to my knowledge no one has done that work yet, but I haven’t seen anyone establish why insider trading is a net bad for society, other than intuitive reasoning.
I fear we're still deep in the "somebody, somewhere, might be making a profit" bog.
But, I do agree that (at least) an attempt to make insider trades more transparent does help inspires confidence.
First movers always win.