I don't have a good sense for the size of the ecosystem. I had assumed that 1.5Bil of some ico coin was X amount of ETH * current ETH exchange rate. But that if

I don't have a good sense for the size of the ecosystem. I had assumed that 1.5Bil of some ico coin was X amount of ETH * current ETH exchange rate. But that if you actually tried to sell all of that it would collapse the market, so if gun to your head you tried to cash out with $1.5 billion USD you'd "only" get $100mil or something.