burst of ICO bubble likely won't take down the whole economy. BTC contracts are high return + extremely high risk, which are typical traits of junk bonds, meaning they won't be treated as investment-grade securities.
You have all heard it for sure. I am just laying out the fact that low-grade securities won't move the market as much as people thought they would. BTC is an exception on popularity given everyone knows about it, but it doesn't change the fact that BTC contracts will never be rated as A/AA/AAA given its ridiculous level of volatility.