Biotech Stock Down 50% Today

Analysts are taking a hatchet to their price targets

While Apple (AAPL)earnings are dominating headlines today, a handful of biotech stocks are also swimming in red ink. In fact, Puma Biotechnology Inc (NASDAQ:PBYI) has surrenderedhalf its value today, and PBYI is so far the worst stock on the Nasdaq by a landslide.

PBYI is down 50% to trade at $19.30, set for its worst day ever by far. The shares earlier fell as low as $18.01 -- a new six-year low. While the company's third-quarter revenue topped expectations, quarterly sales of its key drug, Nerlynx, fell short of estimates.

As such, several analysts have weighed in on Puma Biotechnology. Barclays downgraded the equity to "underweight" from "equal weight," and took a hatchet to its price target, cutting it by 60% -- to $29 from $72. Likewise, J.P. Morgan Securities hacked its price target to $23 from $83 -- a massive 72% cut. Cowen trimmed its price target on PBYI to $68 from $80, and Cantor Fitzgerald dropped its target to $50 from $75, calling it another "messy" quarter for the biotech, but the brokerage firm maintained an "overweight" rating.

While Puma has landed on the short-sale restricted list today, several shorts are likely cheering the stocks' steep decline. Short interest grew nearly 26% during the past two reporting periods, and now represents a healthy 15.4% of PBYI's total available float.

Recent options buyers are also likely celebrating the stock's decline. On the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX), the stock's 10-day put/call volume ratio sits in the 89th percentile of its annual range, pointing to a healthier-than-usual appetite for bearish bets over bullish ahead of earnings.