"The SEC" won't be investigating anyone one in the crypto currency market. It's not their jurisdiction
The Securities Act of 1933 describes securities as things we all understand to be securities: notes, bonds, stocks, etc.
Bitcoin, it's clones and virtually ALL alternative digital currencies are initially generated not by an investment of money, but
by expending computer resources or (mining)
Therefore all cryptographic currencies are commodities.
When digital currrency derivatives begin to surface, this will give "the SEC" some jurisdiction. Until then, they're absolutely powerless in this market.
An example would be the attempted BTC shakeout a week ago on BitFinex where someone used around $3 million to try and break the price below $450, but Bitstamp, Coinbase, and others refused to follow their manipulation.
It was not an "attempted shakeout," actually it's funny that you think someone would execute a $3mill transaction with the sole intent of "shaking someone out" of the market. Hilarious
Someone sold $3mill worth of coin on Finex.. That's it. It happens...
I'm not saying that there isn't manipulation taking place, because there clearly is. But there are many individuals holding $1mill+ worth of BTC who aren't part of this manipulation ring.
That "shakeout" that you make reference to, was merely a single actor who decided to cash out. Hence why there wasn't a universal move across the rest of the exchanges