FTA:

ICOs conclude once the coins or tokens are tradable in the open market.

This is a part that has eluded me thus far: how are the new coins tradable on the open market? I'm genuinely asking - most exchanges don't support all crypto coins, and certainly not the dozens of new ones being created. How does one invest in an ICO and then 'cash out'? I see the ROI stats on some of these ICOs but I'm curious as to if those investors are basically sitting on that ROI hoping it doesn't evaporate before they can sell. Can anyone provide insight here?