Solving insider trading is fundamentally impossible due to the burden of proof.

However I am convinced that forcing people to keep their shares for even just one week would stabilize the markets enough to make insider trading much more obvious (and easier to prosecute). It would also force a shift on perspectives more on the long run, instead of focusing on immediate speculation.

This was a prediction market, not a proper market trade, and I am glad I live in a country where that is outlawed. This is untaxed, unregulated gambling.

It would do nothing. You'd get an increase in derivatives volume with the same underlying effect.