Errr - what?
I think you'll find that market manipulation is prohibited in the US under Section 9(a)(2) of the Securities Exchange Act of 1934, and in the EU under article 12 of the Market Abuse Regulation (etc.)
The US Securities Exchange Act defines market manipulation as "transactions which create an artificial price or maintain an artificial price for a tradable security".
(Sorry, forgot to mention it in the first comment -- that was the whole point of bringing it up in this context.)
But the SEC doesn't regulate mortgages even though there are derivative securities that are regulated. SEC regulates the asset backed securities but not the assets underlying those securities.
If not, it would be a pretty gaping hole in their mandate: "It's fine to manipulate X and profit from that, but not to profit from the regulated derivatives that closely track X."
The CFTC literally just got a fraud statute in 2010
They mostly follow their earlier mandate and the new mandate doesn’t alter it too much
Trying to apply it to spot assets just because a derivative market is affected requires a huge stretch and risk of getting the agency embarrassed and curb stomped in the courts
Edit: I get that many people here are ant-cryptocurrencies, but I think it is rather childish to call it monopoly money.
Products are regulated by the FTC
Commodities and currency derivatives that are traded are regulated by the CFTC
Securities issuance and securities trading are regulated by the SEC
so have fun with the federal trade commission rawr big teeth over there /s