Crazy Action in Medivation After Negative StreetSweeper Post

On Thursday afternoon, well-known fraud busting site,

, posted a negative article on biotech stock Medivation, Inc.

. The piece questions the valuation of the high-flying stock which has risen more than 250% over the last year despite not having a marketed product. Hopes for the company are being pinned on an expensive prostate cancer treatment that has showed promising results in late-stage trials. According to the investors behind the StreetSweeper post, however, the optimism surrounding the treatment has become unhinged from reality - along with MDVN's share price. The piece quotes a former MDVN director who said that “Look, I think it's the most overpriced pharma stock out there,” he bluntly told TheStreetSweeper after selling his own shares. “I don't know what's holding that stock up.” In the wake of the post, MDVN shares immediately plunged on extremely heavy volume, falling from around $86.00 to a low of $80.19 in a matter of minutes. Strangely, however, MDVN shares bounced back almost immediately and were last trading up 0.13% to $85.12. The disclosure at the bottom of the article notes that "through its members, TheStreetSweeper established a financial position in MDVN prior to the publication of this report and will profit on future declines in the share price. It currently holds the following positions in the stock: 45 contracts for the July $90 puts purchased at an average price of $7.25 apiece; 50 contracts for the July $95 puts purchased at an average price of $11.25 apiece; and a total of 38,500 shares of MDVN stock sold short at an average price of $85.44 a share."