Stocks in Motion: Calpine Shares See Power Outage

Updated from 2:55 p.m. EDT

Shares of Calpine(CPN Quote) fell on heavy volume Thursday after the power company reported a wider-than-expected loss attributable, in part, to the mild spring weather. Calpine lost $71.2 million, or 17 cents a share, in the latest quarter, including a 3-cent gain. Analysts had been forecasting an 11-cent loss.

The company said its energy margin was pressured by unusually warm weather. The stock traded down 25 cents, or 6%, to $3.90, on volume of 41.8 million shares traded, making it the most heavily traded issue on the New York Stock Exchange.

Shares of Gemstar-TV Guide(GMST Quote) were active Thursday after the company missed first-quarter earnings estimates and lowered guidance for the rest of the year.

Gemstar, which publishes TV Guide, earned 3 cents a share on revenue of $195.2 million. Analysts polled by Thomson First Call were looking for the company to earn 5 cents a share in the most recent quarter. The company also cut its earnings forecast for the rest of the year, saying that operating income would come in at $20 million to $50 million.

That's significantly lower than the forecast it offered two months ago of $44 million to $69 million. Shares of Gemstar traded down 95 cents, or 16.6%, to $4.76, on volume of 32 million shares.

Shares of Asyst Technologies(ASYT Quote) joined the list of most actives Thursday after the company announced better-than-expected fourth-quarter results.

Asyst reported a fourth-quarter loss of 16 cents a share, 2 cents better than expected. It also had revenue of $130.1 million, which easily outpaced the $108.2 million analysts were expecting. Additionally, the company said it expects to deliver net income of break-even to a loss of 6 cents per share in the first quarter on revenue of $145 million to $155 million. Analysts are looking for the company to report a loss of 4 cents a share on revenue of $124 million. Shares of Asyst traded up $1.45, or 20.9%, to $8.40, on volume of more than 10 million shares.