That's a succinct but false explanation. DTCC does not care if a HF is about to lose a bunch of money and maybe even put a prime brokerage on the hook. Hedge funds make and lose hundreds of billions every week. No prime brokerage would let Melvin end up near insolvency before issuing liquidation margin call and even if there wasn't enough post-liquidation to cover losses, prime brokerages have a collective market cap of more $1 trillion and are easily able to absorb a several billion dollar shortfall. It's obvious to anyone who knows what they're talking about that you are a financial neophyte inventing nonsense conspiracies.