Options trade on HTB stocks, so how do they assign short shares you the buyer the put option, if it is hard to borrow?
You’ll get short those shares, but then it depends on the broker, stock, day - each case is different. Sometimes my broker let me keep such shares for a few hours, other times for several days, other times they may buy them back for me any time they choose. The broker at least must have some shares available to borrow to allow you keep them short, or generally needs to confirm to/follow Regulation SHO: https://www.investopedia.com/terms/r/regsho.asp
The (only) right answer is "call your broker and get clear on their policy". Having said that, this thread is worth checking out:
If you are the seller of a put option and you are assigned, you get stock, you don't get short stock. The holder of the put who exercised gets the short stock.
I think he meant he's the buyer of a put option. For some reason ET ate some of his words in the sentence.