Pretty sure this is trivial. Buy someone’s identity on the dark web to pass an online brokerages KYC then wire money in from an international bank. I say this as person who worked at a fintech. KYC checks aren’t the most robust and you can brute force the knowledge based authentication if you have enough people’s information. Some of the KBA questions you can google because all the data brokers put people’s past cities online.

Why would you need to be anonymous?

I mean, if you spent $$$$ shorting Tesla stock, then a week later the stock nosedived in response to a tweet and you made a big profit, that doesn't prove you were behind the tweet.

It wouldn't even be illegal, unless there was independent proof you were behind the hack. Without that, you just placed a bet which happened to be a lucky one - just like anyone else who was short Tesla.