This is my theory. For the first time, people are able to buy Bitcoin simply by linking their bank account. That means no need for Dwolla, Mt. Gox, etc. and hence no need to understand (or even know about) "the market". I think all this talk about panic sells, big players, reversals etc, is just speculators writing their own narratives. "Who would be so stupid as to buy/sell xxxx BTC at market price? It must be manipulation." The truth is, what we have is a live wire in a bathtub. People who don't know or care about markets want to cash in or cash out immediately, and Coinbase gives them the opportunity to do this, directly, from end to end, at the click of a button. I would bet a lot of people are not even aware that there is a "market".
And for what it may be worth, remember that all SR prices are pegged to the USD. Most users would have their SR interface displaying in USD with the BTC/USD conversion happening implicitly, and only affecting the customer at the checkout. If some "big player" (read: some random rich dude with money to burn) wants to buy a lot of drugs, all he has to do is buy BTC and then immediately part with it to get his products. Market prices do not affect his actions.
I think that all these crazy peaks and dips are natural consequences of increased activity in a (relatively) shallow market, and we should not read too much into them. We have been slowly drifting into a seismic zone -- if you can't handle the tremors, you should move somewhere else.
