As everyone knows, Circle got a lot of cash redemption requests on the weekend they had $3.3 billion trapped in Silicon Valley Bank. What will concern them is that they continue to get cash redemption requests:
Marketcap is now $33,357,305,472, down from $43,511,821,607 on 9th March, just before Silicon Valley Bank got seized by the FDIC. That's a drop of $10 billion.
Why are people continuing to redeem USDC? I think it's because they expect the SEC to declare USDC as an "unregulated security". After all, the SEC stopped Paxos from minting BUSD, and has launched a blizzard of lawsuits targetting Coinbase, Gemini and Binance amongst others. It would be a miracle if they left USDC alone.
If and when the SEC goes after USDC, it will de-peg as soon as the news breaks, because that's how crypto markets work, there is always a frenzy of panicked selling.
So it makes sense to be prudent and cash out well in advance.