To short you merely borrow the shares in question, sell them and expect to repurchase them cheaper to return them. If you borrowed 100 shares at $10 and sell them and the price goes to $100 you owe margin interest on the extra $9000 in value plus $10,000 if you end up throwing in the towel and covering.
If you purchased call options that end up being in the money for you (I believe their are “in the money” calls equivalent to over 100M + shares) the losing side has to produce those shares for you to sell or pay you the equivalent. There was probably some huge out of the money calls bought that cost next to nothing for strike prices in the $10-100 range that will be fat in the money tomorrow. There will be a great weeping and gnashing of teeth...
The guys with naked shorts are gonna be hurting.