Hum i think ICO are more a way for people who already have invest a long time ago in ETH, BTC or else to diversify their capital by buying new token at a rate supposed "cheap".

I don't know if there is a way to know if money from ICO are mainly invested with FIAT (ppl buy btc/eth/else with FIAT and invest in ICO) or if it's already ppl who own BTC/ETH/else. Would be interesting !