[generalpass]

There are many institutional investors such as pension funds and insurance companies (whatever they call their holdings) that rely on returns from things like stocks.

Since they wouldn't be able to sell stocks, they would start selling everything else they've invested in.

Same would go for anyone else requiring cash.

Then everyone holding the other stuff that is liquid, will sell it because why hold onto a plummeting asset when the only reason to own it is the value?