An interesting thought, but in practice, trading derivatives affects the value of the underlying pretty strongly. Whoever is selling you those puts is selling bitcoin (or futures) to hedge, which would drive the price down as you try to put on your position.

With options, buying deep OTM puts won't result in an immediate impact on the underlying market because they have such low delta and market makers aren't going to move a lot of spot to hedge it.

The problem is that if you successfully rook put sellers in this way for some ungodly amount of money, they will never be able to pay out on your claim. Kinda like when all the big Wall Street Banks were caught out because AIG was threatening to go bankrupt and default on their CDS.

You might never exercise the option, but you could probably resell the option at a far higher price

It wouldn't be immediate, but the second you put on a trade with any kind of size that far out of the money, the market makers will wise up.

That sounds like a perfect trade. But doing something like that will paint a target on hacker/s back. So, slowly leaching is a much better idea than getting it in one shot.

I would think a slow-play is significantly easier. For one, it doesn’t require much capital, unlike shorting.

Where would you buy a put (sell) option on Bitcoin (without substantial counterparty or settlement risk)? I genuinely want to know. I would have bought one in November if I could have.

I’ve read about plans to introduce crypto currency ETFs, but I’m not aware of any that are publicly traded yet.

Even then it's not clear you'll be able to buy options on them...

interactive investors offer this i believe

Bitmex