YAHOO [BRIEFING.COM]: The belief that stocks are overbought and that they already reflect positive economic data prompted participants to make a concerted and broad-based push against stocks. That made for an ominous start to September as nearly 95% of the companies in the S&P 500 logged losses this session. Such weakness seemed fitting, though, since September has historically been a weak month for stocks.

Buying interest in the early going helped stocks make a solid bounce ahead of the latest batch of economic data, which featured an ISM Manufacturing Index for August that came in 52.9. Not only was that better than the 50.5 that was expected, but it marked the first time the reading topped 50 since January 2008. A near 10% increase to 64.9 in new orders also proved pleasing to prognosticators.

Pending home sales for July climbed 3.2% to top the 1.5% increase that was widely expected and mark the sixth consecutive month-over-month increase for the tally.

The upbeat reports seemed to support news from The Wall Street Journal that said the International Monetary Fund (IMF) expects the global economy to expand by slightly less than 3% in 2010. The IMF had forecast in July that the global economy would grow by 2.5% during 2010.

Construction spending in July slipped 0.2% month-over-month, which was below the consensus call for 0% growth, but the report didn't receive much attention.

Despite the overall quality of the economic releases, participants quickly turned sides and moved to sell stocks following the data's release. The market's inability to hold the initial gains in the wake of the data suggests that sentiment may be shifting to the downside amid intensifying arguments that the good news is already priced into stocks.

Most of this session's weakness centered on the financial sector, which dropped 5.3% as many of the fundamentally weaker financial stocks that have shown the greatest momentum during the past week buckled. As such, AIG (AIG 36.00, -9.33) and ETrade Financial (ETFC 1.50, -0.26) were the primary laggards in the financial sector. Shares of ETFC were actually among the most actively traded names this session.

Overall trading volume in the NYSE eclipsed 1.6 billion in what was the most actively traded session in nearly one month, suggesting there was plenty of conviction behind this session's selling effort.

Weakness among stocks bled into commodities pits for the second straight session. That caused crude oil futures to reverse a 2.0% gain into a 2.7% loss. Oil prices settled at $68.05 per barrel, just above session lows. Meanwhile, the CRB Commodity Index had made its way to a 0.7% gain before dropping to a 1.9% loss. That marked its second worst loss by percent since July.

There weren't many corporate headlines this session, but automakers were out with their latest monthly sales totals. Ford (F 7.24, -0.36) announced that its sales during August were up 17.0% year-over-year, but that was below the 33% increase that analysts had come to expect amid the Cash for Clunkers program. Ford's competitors Honda Motor (HMC 31.20, -0.13) and Toyota (TM 84.61, -0.58) also reported increases for August, but Ford stated that it has gained retail market share in 10 of the last 11 months.

Corporate announcements are likely to be lacking again tomorrow, but participants will get plenty of trading cues with the release of the ADP Employment Change Report at 8:15 AM ET on Wednesday. Revised productivity data for the second quarter is also due tomorrow morning (8:30 AM ET), followed by factory orders data for July (10:00 AM ET). The FOMC also releases the minutes from its latest meeting tomorrow (2:00 PM ET).DJ30 -185.68 NASDAQ -40.17 NQ100 -1.8% R2K -2.5% SP400 -2.2% SP500 -22.58 NASDAQ Adv/Vol/Dec 563/2.76 bln/2139 NYSE Adv/Vol/Dec 512/1.63 bln/2539