How exchanges/brokers/traders of non-crypto "stocks" have not invaded crypto platforms yet?
What makes you think that stock traders have not invested in bitcoin and other currencies,why do you think that all the alt coins had a huge rally in the past few months and where does the money comes from,there are many big time traders and investors in this sector and so is the reason all the coins are having a rally because these investors might not have the technical ability to understand what the real potential of a coin but they keep on investing in it for a better return.