YAHOO [BRIEFING.COM]: Aggressive selling resumed today, causing the Dow to drop 500 points, the Nasdaq Composite to plummet 5%, and the S&P 500 to sink 60 points to 1200 for its worst single-session performance in more than two years.

Ongoing concerns about the global economy remained a driving force in today's sell-off, which was steady and orderly. Losses were ushered in with heavy share volume, and left the S&P 500 at its lowest level in nine months, or about 12% below its early May high.

Even safe havens like gold and silver failed to escape selling pressure as traders opted to sell their profitable picks in order to meet margin calls on other holdings. Gold settled lower by 0.5% at $1658.20 per ounce after it had rallied to a new all-time high at $1684.90 per ounce. Silver sank 5.6% to $39.42 after it had hit a three-month high of $42.30 per ounce.

The scope of this session's slide has many wondering what the market has in store tomorrow, when the official nonfarm payrolls report will be released. Today, though, participants were dealt a weekly initial jobless claims tally of 400,000, which isn't much better than the 405,000 initial claims that had been broadly expected among economists polled by Briefing.com.

Renewed macro tension in Europe prompted the European Central Bank President Trichet to provide markets with additional liquidity with an extension of maturities related to financing operations. In a similar vein, Japan expanded its asset purchase plan, but also intervened in the yen, which tumbled more than 3% against the greenback before it could pare some of that loss. Weakness in the yen and euro helped drive the Dollar Index 1.8% higher.

Every single sector in the S&P 500 fell more than 3% today. Materials and energy stocks suffered the worst of it all. The two sectors sank 6.6% and 6.8%, respectively.

Retailers weren't far behind, based on the SPDR S&P Retail ETF (XRT 48.55, -3.38), which fell 6.5%. The group's weakness came not only because of broad market weakness, but also from a generally uninspiring batch of monthly same-store sales results. Although it didn't offer any monthly metric, teen apparel and accessories retailer Aeropostale (ARO 12.53, -3.99) saw almost one quarter of its market cap melt away after the company cut its guidance.

Dow component Kraft (KFT 33.78, -0.52) had gapped up by about 6% to a multi-year high at the open, thanks to news that the company will spin off its North American grocery business, but the blue chip was ultimately imbued by broad market weakness.

Concerns about global economies continued to wreak havoc on commodities today. In turn, the CRB Commodity Index dropped 2.8% to a near seven-month low.

Oil suffered one of the steepest drops. Specifically, crude oil prices settled at 86.63 per barrel for a 5.8% loss. That marked its greatest single-day drop since May 5 -when it fell more than 8% - on the back of concerns about global economic health. Futures prices had recorded intraday lows of $86.04, which marks the commodity's worst level since February 18.

Natural gas prices closed lower by 3.4% at $3.95 per MMBtu. Futures prices had actually traded higher in early pit trade, but bearish inventory data spurred a reversal that took the commodity as low as $3.92 per MMBtu, which made for its worst level since mid-March.

However, safe havens like gold and silver benefited from weakness in the broader commodity complex and a plunging stock market. In morning trade, December gold, which eventually settled lower by 0.5% to $1658.20 per ounce, rallied to a new all-time high at $1684.90 per ounce. September silver, which lost 5.6% to close at $39.42, traded back above $42 to a three-month high of $42.30 per ounce. The late morning plunge suffered by the pair of precious metals took gold as low as $1642.20 per ounce and silver down to $38.47 per ounce. Many traders attributed the sell-off to liquidation that followed margin calls in other asset classes.

Advancing Sectors: (None)
Declining Sectors: Energy -6.8%, Materials -6.6%, Financials -5.2%, Industrials -5.4%, Consumer Discretionary -4.8%, Tech -4.5%, Health Care -3.8%, Telecom -3.3%, Utilities -3.2%, Consumer Staples -3.1%DJ30 -512.76 NASDAQ -136.68 NQ100 -4.6% R2K -6.0% SP400 -5.9% SP500 -60.27 NASDAQ Adv/Vol/Dec 203/3.27 bln/2442 NYSE Adv/Vol/Dec 140/1.82 bln/2968