You can short on Robinhood if you have a qualifying margin account. My shorts are actually at a different broker.

I have used options at times, but I find that they tend to behave weirdly with this strategy. I think they would work if I picked out the right spot on the options chain but I want to do a rigorous analysis before I try them again.

Edit: correction; i guess you can't short on Robinhood without using options. I thought you could with Robinhood gold, but like I said my shorts are elsewhere.