I don't know but my guess would be:
one has bitcoin, knows it's real money but it's boring and doesn't grow fast enough to buy lambo next week, uses btc as collateral to buy some shitcoin on steroids expecting turbo surge, then mafias decide (well timing by the way, congrats) to sell the btc they stole, which puts pressure on the collateralized asset which gets force liquidated and one has nothing left︀ other than some worthless centralized token and panic sells to safe at least something, hence︁ the impact on the price
just my one minute theory... things are usually more complicated︂ though