Stocks trended downward after Tuesday's solid finish, and

Finisar

(FNSR) - Get Report

was among the losers after posting disappointing preliminary results.

The Sunnyvale, Calif.-based networking-equipment maker said it brought in sales totaling $105.7 million -- a hair under the year-ago figure and just below Thomson Financial's $108.2 million estimates. Shares lost 34 cents, or 9%, to $3.42.

Guess?

(GES) - Get Report

also fell after predicting full-year earnings of between $1.79 and $1.84 a share, which leans to the lower end of the consensus.

For the fiscal second quarter, the Los Angeles-based company earned 40 cents a share on revenue of $388.3 million, beating expectations. The company earned 22 cents a share on revenue of $261.9 million in the year-ago period. The apparel maker and retailer also upped its dividend by 2 cents to 8 cents a share. Still, Guess? stock was off 7.3% to $49.50.

Chesapeake Energy

(CHK) - Get Report

traded higher after the oil-and-gas driller said it plans to sell assets which it expects will ultimately yield around $3.5 billion over the next nine quarters. Chesapeake also said that in light of low natural gas prices, it will temporarily cut down on most of its gross natural-gas production.

In addition, the Oklahoma City-based company will reduce its operated-drilling-rig count by the end of the year. That should save it $1 billion through 2009. Shares were up 1.5% to $33.31 in recent after-hours trading.

Semiconductor firm

Avanex

( AVNX), of Fremont, Calif., climbed 3.5% to $1.76 after

swinging to a non-GAAP profit of $49,000. The stock broke even on a per-share basis, compared to a penny-a-share loss last year. That's in-line with the average analyst estimate.

And

YM BioSciences

( YMI) shares jumped 8.3% after the Canadian drugmaker announced positive early-phase preliminary results for nimotuzumab, which is proposed to treat patients with lung cancer who are unsuitable for radical chemotherapy.

YM said that the compound, which was tested in combination with radiation, resulted in a "clinical benefit" in all 13 subjects enrolled in the first two cohorts of this phase I/II study. There was a "reported absence of side effects," said YM, and "relatively long survival times" were observed in the first cohort. Shares were trading at $1.70 after the bell.