So after a little scare the cash will all come back to the stock market.
I think you're right, mainly because of the bond situation you also mentioned. If the 10-year bond was paying, say, 6%, folks just might park their investment money in bonds, and leave it there.
But the Fed has taken away that option. Folks have no choice but to eventually drift back into stocks. Of course, the key word is "eventually". I haven't figured that part out yet.
I was just telling my wife something similar. The money has to go somewhere. There is no inter-dimensional portal that sucks only money into it.
OTOH, credit is money. If people simply default, the money goes away the same way it came in - as a vapor.