MARKET SNAPSHOT: U.S. Stock Indexes Ride Volatility Higher

By Kate Gibson, MarketWatch

NEW YORK (MarketWatch) -- U.S. stocks climbed on Monday, with the S&P 500 extending its longest win streak since July, as Chinese exports beat projections and as investors anticipated the unveiling of its new iPhone models.

"China came out with significantly better economic data over the weekend, and that's important to us because the China demand story continues to be a very important piece of the global economic picture," said Art Hogan, market strategist at Lazard Capital Markets.

"There's excitement about the Apple product announcement tomorrow, and Apple is one of the largest components of the S&P 500. And volumes are low and participation is still timid, so any moves get exaggerated, very much like we saw in the volatility on Friday," Hogan added of the end-of-week session, which had the Dow Jones Industrial Average (DJI) crossing zero 11 times.

On Monday afternoon, benchmark indexes were at or near session highs, with the Dow industrials positioned for their best performance in more than eight weeks, and recently up 160.91 points, or 1.1%, to 15,083.41. Caterpillar Inc. (CAT) and Alcoa Inc. (AA) led gains that included all but two of the blue-chip index's 30 members.

Heavy-equipment-maker Caterpillar rose 3.1% and aluminum producer Alcoa gained 2.2% after Beijing's General Administration of Customs reported Chinese exports rose 7.2% in August from the year-earlier period.

The S&P 500 index (SPX) climbed 16.84 points, or 1%, to 1,672.01, with materials and information technology pacing broad gains that included all of its 10 major industry groups. The Nasdaq Composite index (RIXF) rose 47.15 points, or 1.3%, to 3,707.16.

Apple Inc. (AAPL) rose 1.9% before an investor event where the iPhone maker will unveil upgraded versions of its smartphone.

Molex Inc. (MOLX) jumped 32% after the manufacturer of electronic components for products including Apple's iPhone agreed to be purchased for $7.2 billion by Koch Industries Inc., the holding company run by the billionaire Koch brothers.

Delta Air Lines Inc. (DAL) gained 8.5% after S&P Dow Jones Indices said the carrier would replace BMC Software Inc. (BMC) in the S&P 500.

For every stock on the decline, roughly four rose on the New York Stock Exchange, where 337 million shares traded as of 2:25 p.m. Eastern.

Composite volume surpassed 2 billion.

The thinly traded market comes in a "historically difficult month" for stocks, and follows a trend that had "a significant amount of risk" coming out of equities in August, with the S&P 500 losing 3.1%, noted Hogan.

While many Wall Street professionals are back at their desks after summer breaks, the low volume and high volatility is likely to continue "until we get resolution in a lot of the September issues," said Hogan.

With Congress back in session, those issues include potential U.S. military strikes against Syria, the budget-debt ceiling and approving a replacement for Federal Reserve Chairman Ben Bernanke, with President Barack Obama expected to nominate someone in coming weeks.

Treasury yields fell, with the benchmark 10-year note used in figuring mortgage rates and other consumer loans off four basis points at 2.893%.

The dollar fell against the currencies of major U.S. trading partners including the euro (EURUSD) but excluding the Japanese yen (USDJPY).

The cost of energy declined, with a barrel of crude (CLV3) priced at $109.52 a barrel, down $1.01, or 0.9%, on the New York Mercantile Exchange.

Gold futures(GCZ3) gained 20 cents to $1,386.70 an ounce.

Wall Street on Friday finished higher for the week as reports indicated increased global economic growth even as investors weighed possible U.S. military action in Syria and chances of the Federal Reserve cutting back on its monetary stimulus later in the month.

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