(FORTUNE Magazine) – Call it the nightmare on Wall Street. This Friday the 13th, the market looked even scarier than the movie, with the FORTUNE e-50 index losing a full 14.5% over the past two weeks. That extends a downward spiral that began in September. The sole gainer in the bunch was AOL, which eked out a meager 2.3% return. The remaining 49 all headed down, led once again by Priceline.com. The stock dropped a full 49.4%, to just $5, after announcing it was quitting the name-your-own-price business for gas and groceries (maybe this means a merciful end to those William Shatner ads). Razorfish was a close second, losing 47.1%, and another eight stocks dropped 30% or more. The e-50 wasn't alone: The Nasdaq dipped below 3100, matching its lows of late May, and the FORTUNE 500 index lost 4%. For updates, charts, and more, visit our new Website, indexes.fortune.com.

--Julia Boorstin