Or, and I beg you to consider this radical position: we arrest people who break the law (insider trading is illegal) and those who knowingly help them to do so (the operators of the prediction markets).
How quickly we accept the death of even the ideal of rule of law in favor of embracing a return to an explicit rule by might, fuck-you-got-mine mentality.
It doesn't break the law.
From Wikipedia[0] because I can't be bothered to read more than a few paragraphs:
> In 1909, well before the Securities Exchange Act was passed, the United States Supreme Court ruled that a corporate director who bought that company's stock when he knew the stock's price was about to increase committed fraud by buying but not disclosing his inside information.
Based on anti-fraud common law alone the court decided it was illegal for an insider to trade stocks with non-public information. An explicit law would be nice, but a reasonable interpretation of basic law would see most of our ruling class behind bars. This is only highly-contested and technical because we've let our standards slip so far.
0: https://en.wikipedia.org/wiki/Insider_trading
If it doesn’t then it should.