Stocks slumped at the opening. Earnings disappointments, rethinking expectations for a Fed rate cut and soft economic data gave markets little incentive to take risks ahead of Wednesday’s Fed decision.

The NYSE composite was down 0.6% at 10:19 a.m. ET. The Nasdaq was down 0.2%, the Dow 0.4% and the S&P 500. Initial volume appeared higher than in Monday’s opening.

The Fed funds futures bias toward a potential rate cut Wednesday shifted lower, with 86% of participants banking on a short-term rate trim to 4.5%. That’s down from a 98% bias at Monday’s close.

But those odds might be turning higher after a much weaker-than-expected decline in consumer confidence.

Stocks had been paring losses ahead of the 10 a.m. ET release, but edged back down on the gloomy sentiment.

Earlier, a survey of 20 major cities by Standard & Poor’s Case-Schiller Index showed home prices were down 4.4% in the year through August. Ten of those cities showed 12-month price declines above 5%, the fastest decline since 1991. Tampa led the train wreck, with a 10%+ price decline. Index authors said “The fall in home prices is showing no real signs of a slowdown or turnaround.”

Energizer Holdings () tumbled 7.72 to 102.94. The company reported a 54% increase in fiscal Q4 earnings. That topped analyst estimates. Energizer reported flat sales in its namesake batteries business, as the company raised prices to offset lower volume sales. It also said it expects earnings contribution from the $1.6 billion Playtex Products acquisition to roll up slowly through 2008 and 2009. The move dropped the stock below its 10-week moving average.

Corn Products Int’l () dropped 6.28 to 42.01. The maker of corn syrup sweetener reported a 38% rise in Q3 earnings, just below expectations.

US Steel () fell 6% and Commercial Metals () sank 13% after the metals firms missed views. Other steel and metals firms retreated, including Mittal () and Schnitzer Steel ().

China-based Internet portal Sina () jumped up for a third straight session, adding 98 cents to 57.93. The stock broke out of an eight-week cup-with-handle in September. It is 28% above the base’s 45.02 buy point.

Sina rallied on strong results late Mon. by rival Sohu.com (), which climbed 6% to a new high.

9:15 a.m. ET Update: Stocks To Open Lower As Fed Meeting Starts

By Vincent Mao

Stock futures pointed to a weaker open Tuesday. Nasdaq futures dropped 12 points, S&P 500 futures lost 6 points and Dow futures 54 points.

Today marks the start of the Federal Reserve’s two-day meeting. To help relieve the pressure from the subprime turmoil, a rate cut of a 25 basis points in widely expected. The decision will be announced Wednesday.

But published speculation that maybe, just maybe, the Fed won’t cut rates Wed. may be making investors a little nervous.

Consumer confidence for Oct. will be out at 10:00 a.m. ET. Economists expect a dip to 99.5 from 99.8 in September.

Crude oil futures pulled back from record highs. The December contract lost $1.11 to $92.42 in electronic trading.

Meanwhile, the dollar rebounded from all-time lows against the euro.

Smith & Wesson () shot down 24% in pre-market trading. The gun maker pegged second-quarter earnings between 5 cents and 7 cents a share vs. views of 12 cents. Sales are expected from $69 million to $71 million. Analysts expected $82 million. Smith & Wesson also cut its full-year profit and revenue outlook.

Atheros Communications () jumped 8% in the preopen. Late Monday, the chipmaker reported a 47% rise in earnings and a 34% increase in revenue. both were above views. The company cited strong sales of its networking products.

CF Industries () grew 9% in the premarket. Late Monday, the fertilizer maker trounced views as its Q3 income surged 436% to $1.50 a share. Sales jumped 46% to $582.9 million, the best growth in many quarters.

Under Armour () reported third-quarter earnings of 40 cents a share, up 25% from a year ago and 6 cents ahead of views. Sales also came in above estimates. But the stock dropped 8% in pre-open trading.

Volcom () plunged 23% in the preopen. After the bell Monday, the apparel maker delivered third-quarter earnings above views, but gave a weak outlook. It sees Q4 income between 30 cents and 32 cents on sales of about $70 million to $73 million. Analysts expected 47 cents on sales of $82.3 million. Full-year profit is expected at $1.37 to $1.39 a share vs. estimates of $1.50.