1) The pre-$135/btc long term holder, who knows that right now btc's true value is not ~$200 and they will not buy at that price, when a discount may be around the corner, and feel btc's true value is around $100-$150.
2) day traders, don't care what the price is but the market volatility just now is not inviting to participate in.
3) October 2013 new blood from recent spike, to these folk anything under $230 is a good price as they have seen it's potential. They are probably the ones fueling this dance around the $200 mark.
A lot of excitement about the price rise recently but it appears to have no determination to continue. i think we are looking at $140 - $170 without a panic, in the following weeks. With panic who knows....The Chinese love their money, if it starts disappearing in front of their eyes....
4) True believers which think everything below $10,000 is too cheap to sell.
5) Ultimate believers that measure all their gains and losses in bitcoins and are hell-bent on increasing their bitcoin balance in every opportunity. "Selling" in their terminology is obtaining more bitcoins and USD is only relevant in the timing of gaining more coins.