Seems a bit more coordinated than that. Some whale operating on Stamp has been keeping the market down all last week.
Oh c'mon, how do you REALLY know that some "whale" is doing this on purpose? How do you KNOW??
Also volume does not equal quantity of Bitcoins. Compared to what I was like a few months back, I have been pretty inactive in Bitcoin of late, Still, in the past 3 weeks, I have probably account for 150 Bitcoins worth of trade, with all my entries and exits from the market. I currently hold just 15 BTC. So perhaps a rule of thumb would be to divide volume by 10 in order to find the real amount of Bitcoins that the market has a capacity for holding and in reality, you would have to divide the total volume with a much greater number than 10 in order to find out how much Bitcoin the market players are holding or capable of buying/selling.
Here's another way to calculate. The volume on Bitstamp right now is around one-tenth the total volume of all exchanges, according to here:
http://bitcoincharts.com/charts/volumepie/If you were to drop one-tenth of the SR coins (about 3000 coins) right now onto Bitstamp, unexpectedly, in one big market order all at once, the slippage would drop the market by about $45 per coin. Then it would immediately recover a significant chunk of that $45 when people saw the cheap coins and placed orders that they had not placed as limit orders. That tells us that the flash $80 drop was an overreaction.