Even if the fund tanks, they can set up a new one, probably with sympathetic money or just cruise off into the sunset with their millions.
The problem is bigger than originally conceived then.
The existence of billionaires isn't even good for the free market, let alone free society. In order for a market to be rational, the threat of losing money has to actually mean something, which it doesn't for the ultra-rich.
The problem is systems that resist merit. You make terrible investment decisions with the portfolio but it doesn't matter? (I think it will matter FWIW.)
In the meantime, the billionaire owner of Citadel (the company that just made tons of money by front-running all these retail investor trades via their data harvesting contract with Robinhood) just used some of that freshly-acquired cash to buy a stake in Melvin (the company that those retail investors just tanked) for pennies on the dollar. The feel-good rage of WSB serves as a convenient smokescreen for the rich getting richer.
You're starting to get it.
On Money: Plotkin's fund lost money for his investors, all of whom are rich people who will be upset with him. There will probably be some redemptions, and AUM will go down -- not just because he lost some of it, but because investors will pull out some of what remains.
On Reputation: Plotkin ends up with egg on his face because he held the bag for a bunch of mom-and-pop investors on Robin Hood. You know how Soros is known for famously breaking the Pound Sterling? Plotkin is now known for infamously being broken by GME.
On Relationships: Plotkin lost even after getting an injection of liquidity from Cohen and Griffin. That can't be good for his standing with those two power players.
I don't buy it.
Also the collateral damage is going to be more interesting to follow than the financials themselves. Already Discord and RobinHood painted themselves as enemies of the people - whether this was their least bad option legally, or they were influenced by Wall Street is immaterial - it's already viewed as the latter. Couple that with other high-profile bans by social media platforms this year (and it's not even February!), and I can see a lot of regular people all across the political spectrum who feel abused by big, rich companies. I think the last time we saw this kind of energy on the Internet, it led to Scientology protests, Occupy WallStreet and the Arab Spring...
This is like that scene in 300 where Leonidas makes Xerxes bleed. The point isn't that Wall Street has fallen. It's that, for once, Wall Street is fallible.