The mother of manipulators want to come into cryptocurrencies? Not too bad but we should be ready for high level of price manipulations as we know how those guy do manipulate stocks price. However this is also a good news as we can find out that at list this will be an adoption.
Wouldn't that make markets more interesting to trade into? Let them manipulate market so long as they can, let's just try to ride the wave they will create. You are right though that this news is a significant boost in adoption rate of cryptocurrencies in general. Nevertheless, I do hope that those big players of stocks wouldn't overdo the manipulation, since it can be unhealthy for btc and crypto in the long run.