Stop losses don't protect you if the fall is rapid enough and there are no buyers. Your order simply won't get executed (at least not where you want it). That's what I think will happen if the Bitcoin bubble bursts. Being 'intelligent' doesn't protect you from reality. But I'm sure you knew all that, and don't _deserve_ to lose your money.

I wonder how that would work in reality. There are so many exchanges. You’d have to do a massive coordinated effort. Any “massive” drop on a single exchange would be seen as a great arbitrage opportunity and get eaten up.

There are a lot of exchanges. But YOU (or any person in particular) trying to cash out at any point in time will need to move your coins to that exchange (and create an account, etc), and then try to sell. There aren't a lot of buyers when a bubble is popping. And not much potential for arbitrage when everything is going down. And with Bitcoin's slow confirmation rates, I think it would be worse than a typical stock market. No, if the bubble pops, it's going to be bad for everyone involved.

This has already happened in reality with ETH on GDAX:

https://www.google.com/amp/s/www.cnbc.com/amp/2017/06/22/eth...

It's very unlikely a stop loss will help you in case of a bitcoin 'run'.