Yep, the day the Expedia news came out, the price was at $630. Price didn't budge at all. Then the very next day, wham! A fkn FUD storm about threats of 51% attack (again, every 4-6 months, for years now... ad nauseum), +Stamp FUD, + China FUD, +Bitfinex FUD, all on the same day. And then a bunch of panic selling ensues all the way down to $530, for no good reason at all. And you know what? No one even remembers that now, or if those stupid fears were even warranted. Here's a hint: they weren't.
The bitcoin community is, and will continue to be, pathetic, until it puts on its big boy pants and grows the hell up. Stop panic selling over nothing. Otherwise, the bitcoin world hasn't even seen what the governments of the world can cook up in regard to media-created FUD, until they feel the need to.
IMO it's mostly just amateur knob day-traders (hello Speculation forum participants!) following the Mantra "he who dumps first, dumps best".
And, if it's not that, it's all of the new corporate mines that have popped up. Generally, IMO, they're not interested in Bitcoin other than to load up on fiat, and since these operations are huge they're taking most of the newly mined coins and dumping them on the market for fiat. In years past, the mining base was much more spread out and mining participants, on average, were more intereseted in building BTC reserves than the fiat equivalent. This concept coupled with the fact that at low prices the daily volume was
much greater meant that any new coins mined that
did make it to market had little effect on the exchange rate. Now, with higher price, lower volume, and corporate mines with no interest in holding BTC you get an ever increasing supply of fresh coins comparative to historical time frames.