You can't put a stop loss on an option, you can do a stop limit order, however this is assuming someone wants to buy out your contracts. You can also put a counter long or short position to counteract the market going against your option, however, it wouldn't have been enough to offset such a large loss. The main issue here is the fact that they're shorting the market which is much harsher than a standard "put" option. They essential got loans to get leverage for betting against a company, they can maintain their position if they do not default on their loan payments. Keep in mind those payments are going to go higher and higher as time+price increases against their initial bet. If they end up defaulting on their loans they (or the insurer) will have to exercise the right to buy those shares at current market price which would completely btfo the majority of hedge funds atm.