NorthWest Biotherapeutics Inc (NWBO)

[beachlifeisfun]

The sudden drop in NWBO's sp that day is analogous to what happened to Dendreon:

Just minutes before 12:30 pm central, Dendreon’s stock price began to fall. It didn't just fall--it nosedived from $24 to under $8 ... in 75 seconds. During a period of 75 seconds, more than 4,000 trades were placed, totaling 3 million shares, or about 50% of Dendreon’s (spectacularly high) average daily volume. Given that the message board poster knew what was coming more than two hours beforehand, and predicted the timing almost precisely, it is a safe bet that this was a coordinated, illegal naked short selling attack. And just in case you still didn’t get this – it caused Dendreon’s share price to lose more than 65% of its value – in just 75 seconds flat.

What was the daily trade volume vs. average volume on that day again?
and as for those puts?

One such strategy is known as a “married put.” Normally, a hedge fund buys from a market maker a certain number of put options—the right to sell a stock at a specified price at a specified date. If on that date the stock has lost value to the point it is below that specified price, the buyer of the put option (the hedge fund) makes money, and the seller (the market maker) loses money. To hedge the risk that he might lose money, the market maker, at the same moment that he sells the put option, also short sells the stock. This is perfectly legal.

But some market markers conspire with hedge funds to drive the stock price down. Instead of merely shorting the shares into the market, the market maker naked short sells the shares, and, importantly, sells those phantom shares to the same hedge fund that bought the puts. As a result, the hedge fund manager winds up with the puts and a matching number of shares (actually phantom shares that are never delivered to him, but about which he never complains, or forces delivery, as that would create upward pressure on the stock, the precise opposite of what he wants). Because the puts and the phantom shares are equal in number and arrive together at the hedge fund, they are known as "married puts".

Once in possession of the phantom shares, the hedge fund manager proceeds to fire them into the marketplace. But he is able to say that he never naked shorted because all he has done is sold the shares that he bought (wink wink) from the market maker.

Either way, the effect is to flood the marketplace with phantom stock. The hedge fund makes money. And the market maker is rewarded with more business selling married puts.
Incidentally, the fee charged for such puts do not follow any normal option model pricing (in fact, the exchanges search for married puts by looking for options that are mispriced in relation to Black-Scholes, the standard formula that prices options). That is because their pricing is not really a function of any math or statistics, but is a function of the willingness of the hedge fund to pay the option market maker to help him break the rules against naked short selling. And that willingness is a function of how difficult it is for the hedge fund to use other loopholes to break those rules.

In the slang of Wall Street, these married puts are known as “bullets.” Through their maneuverings, the option market maker and hedge fund manager synthesize a naked short position that puts “bullets” into the hands of the hedge fund. The hedge fund fires those “bullets” at the stock to make it collapse, timing the last “bullet” to fire as the hedge fund’s put option expires profitably. If the option position nears expiration and looks like it will expire at a loss (“out of the money”), the hedge fund manager goes back to the option market maker, and together they reload by synthesizing more “bullets.”

I've posted this before, but for any folks who are interested and missed it the first time, you can find the full story here:
http://www.deepcapture.com/wp-content/uploads/2009/10/story-of-dendreon.pdf