You can actually short it on Bitfinex, they actually allowed margin trading of BSV a few months back.  According to the
https://bfxrates.com/

Site for BSV, the funding rates are very high between 0.20-0.40% a day, and the price is so low right now that it might be risky shorting it due to a possible short squeeze in the near future.

My advice, wait for a bounce and maybe short it then.