Well, they can jump... if they still have some left. I don't see crypto suddenly booming from a stock market collapse though. Especially if said investors haven't been into cryptos before. It would also require they take their remaining money out of the stock market and transfer that to cryptos, which might not always be easy.
if the stock market collapses, it might be a Crypto revival, because the stock market is very dependent on fiat currencies, whose value changes according to the conditions of each country, if a crisis occurs, what happens is hyper infiltration, helping the world economy is bitcoin, because bitcoin will not be affected by the condition of any country, and bitcoin is global, this can be a very good alternative for the business world.