Seems that the price of btc has maintained right around the $800 level on all exchanges for a fairly long time (except for Mtgox) - and it is doing so a little bit too conveniently. With the stock market making big moves and various big news stories coming out about Turkey, Argentina, BTC china accepting deposits again, etc, you would think there would be bigger moves. My guess: the large btc holders are trying to reduce volatility in btc to remove this stigma about it. They do so by capping rises and putting a floor on dips. Manipulation is manipulation. Let the market take it where it wants to go.
I just came on here to post this exact same thought and found this thread right at the top.
I speculate that large holders are getting the message that bitcoin is too volatile and are buying and selling bitcoins to maintain $800. The other theory I have is that the Bitcoin Investment Trust has issued guidance to its trader to buy bitcoins if it gets near $800.
The bitcoin purchases are probably absorbing bitcoins being dumped by retail companies selling their bitcoins into the market.