Is there a general consensus on how much volume it takes to move the BTC market price? 
Is the SEC not worried about market manipulation? 
Is there a legal framework in place to deter / reprimand BTC manipulation? - I realize this could only apply to US patrons.

My theory was that BTC was too susceptible to manipulation to issue an ETF yet.  Apparently I'm wrong, which is understandable, because I make beer for a living...

Any friendly opinions welcome!