The mostly likely quantum attack on Bitcoin will be a catastrophic transfer of large wallets to burn addresses along with a massive short position. No need to worry about washing stolen coins when you can just enjoy your "well timed" legal short position's windfall.
two things: 1) Short markets in Bitcoin don't have unlimited depth, and the centralized ones are KYC'd so there's some risk there 2) What if it doesn't tank the price? One thing people have suggested is just burning all the vulnerable coins[1]; it reduces supply so maybe the price will... go up? The point is there's uncertainty. [1] https://x.com/lostbutlucky/status/2040878873731080681
It will also tank the price because by doing it, you have demonstrated you have complete control of bitcoin transfers, you can transfer bitcoins from anywhere to anywhere else at any time, and that there is no way to flag it as illegitimate because mathematically you're just providing the correct numbers.