they have terrible names. I can never remember. A put option I think gives me the right to sell you a stock at a price.

So say, ACME is trading at 110. I can buy the right to sell you ACME at 100. You say ok because it's at 110.

But then ACME crashes to 50.

I buy it at 50 and you are on the hook to buy it from me at 100.