A short is just a loan and a contract. If you can find your own counterparty, you might be able to do it.

I thought about this, but who would make a loan to somebody they don't know without a platform with sufficient guarantees?

And anyway, it would need to be BCH which is already on one of the few exchanges that allow to trade it, as it's impossible for the time being to move it around (which is the very reason why the price is high there right now). Not very likely.

On the other hand, if anybody who is long on BCH wanted to talk about a future or an option, I'm all ears :D

Sufficient guarantees are just a contract. The result is the same either way if something goes wrong -- you take the counterparty to court.

In this case, by "sufficient guarantees" I meant the automation of exchanges, where you need to have collateral to trade on margin, and the lender is automatically repaid (unless something goes very wrong) without courts.

So then write a contract that requires collateral. This is what escrow exists for.