I don't know if the realization that politicians in top democracies like the US are also very much involved in corruption should be a solace to me like 'oh so it's not only in Africa, that they have chronic corrupt politicians, it's a shame that politicians are almost all the same everywhere.
I don't see how you can stop insider trading if you still allow where they cash out their inside information being the prediction sites, as long as prediction market exists I don't see how you can totally eliminate insider tradings. The politicians only need to give signals to their cronnies to get the job done so as far as they have communication with the outside world the deal will surely continue, maybe minimized but I don't think it can stop. Corruption is like cockroaches, no matter how you fumigate you can't kill them all, when the hit dies down they will start creeping out and be multiplying.
The trick is that, in nations where it is illegal for politicians to actually own anything, they just circumvented that by getting their family to do the same, or their friends. Sure the government could still check that, but if your party rules the country, then you can even murder and get away with it depending on the power of your party. Trump was literally mentioned in Epstein files and nothing happened, so believe me this corruption of insider trading will not end, as long as you have the power you can do anything you want.
Back to the topic, OP is about preventing officials from participating insider trading and not a common man or at least this is what I understood on my second attempt of reading the open post. Insider trading on a whole should be prohibited but here it seems that they are blocking government officials at least.