Insurance could solve the problem. I wonder if the ETFs are required to have insurance. So long as folks don’t get fully rugged then perhaps we’ll be alright. 

HardRich

I was thinking about this recently, the tradfi way to mitigate these types of risk is to take insurance products on them, but then the insurance providers would need to hold sufficient Bitcoin in some sort of custody to cover losses? But that doesn’t work with an asset with limited supply.