Updated from 1:03 p.m. EST

Shares of ESS Technology ( ESST) were among technology's losers Thursday, falling 16.7% after the company's earnings disappointed Wall Street.

Excluding items, the chipmaker posted a loss of $19.7 million, or 50 cents a share, on sales of $43.1 million in the quarter. Analysts polled by Thomson First Call were expecting a loss of 18 cents a share on sales of $43.9 million. The company said that lower-than-expected demand for digital media products during the quarter contributed to the company's loss. Looking ahead, ESS expects a first-quarter loss of 23 cents to 28 cents a share on sales of $33 million to $38 million. Analysts had been expecting a loss of 14 cents a share on sales of $43.1 million. Shares traded down $1.02 to $5.08.

BMC Software ( BMC) fell 11.5% after the company posted third-quarter earnings above expectations but warned that fourth-quarter earnings would be below expectations. Excluding items, the company earned 22 cents a share on sales of $386.8 million. Analysts were expecting earnings of 21 cents a share on sales of $389.4 million. Looking ahead, BMC said that it would earn 17 cents to 22 cents a share on sales of $410 million to $425 million. Analysts had been expecting earnings of 23 cents a share on sales of $415.8 million. Shares traded down $1.95 to $15.05.

Shares of American Superconductor ( AMSC - Get Report) rose 11.5% after the company posted third-quarter results that topped forecasts. The maker of electronic converters posted a loss of 9 cents a share on sales of $23.2 million. Analysts were expecting a wider loss of 21 cents a share on sales of $16.5 million. As a result of the third-quarter results, American Superconductor raised its full-year sales guidance to a range between $58 million and $61 million, up from $55 million to $60 million, and said that losses would be 58 cents to 64 cents a share, lower than its previous guidance of 70 cents to 82 cents a share. Analysts had been expecting a full-year loss of 74 cents a share on sales of $56.1 million. Shares traded up $1.31 to $12.66.

Amazon.com ( AMZN - Get Report) fell 14.6% after the Internet retailer posted fourth-quarter earnings that fell below expectations. Excluding a tax gain, the company posted a pro forma profit of 35 cents a share on sales of $2.54 billion. Analysts were expecting earnings of 40 cents a share on sales of $2.42 billion. Looking ahead, the company forecast first-quarter sales of $1.8 billion to $1.95 billion and full-year sales of $8.05 billion to $8.65 billion. Analysts are expecting first-quarter sales of $1.85 billion and full-year sales of $8.1 billion. Operating income is expected to be between $385 million and $510 million. The disappointing fourth-quarter results prompted Credit Suisse First Boston to cut its rating on the stock to neutral from outperform and lower its price target to $40 from $54. Shares traded down $6.13 to $35.75.

Shares of Asyst Technologies ( ASYT) rose 6.2% after the company posted third-quarter results that beat expectations. The semiconductor equipment maker posted a pro forma loss of 4 cents a share on sales of $161.4 million. Analysts were expecting a loss of 12 cents a share on sales of $135.8 million. Looking ahead, the company forecast fourth-quarter results that are in line with expectations. Asyst expects to post a pro forma loss of 10 cents to 14 cents a share on sales of $120 million to $130 million. Analysts are expecting a loss of 14 cents a share on sales of $123.7 million. Shares traded up 27 cents to $4.61.

Other technology movers included Cisco ( CSCO), down 63 cents to $17.52; JDS Uniphase ( JDSU), down 3 cents to $1.99; Microsoft ( MSFT), down 28 cents to $26.18; Intel ( INTC), down 12 cents to $22.38; Sun Microsystems ( SUNW), down 13 cents to $4.26; Sprint ( FON), up 12 cents to $24.60; Oracle ( ORCL), down 22 cents to $13.34; MCI ( MCIP), up 47 cents to $20.15; and Lucent ( LU), down 8 cents to $3.19.