Oct. 6 (Bloomberg) — U.S. stocks fell, with the Standard & Poor’s 500 Index halting a two-day advance, as small-cap shares resumed a selloff and investors awaited the start of corporate earnings season to assess the strength of the economy.

Micron Technology Inc. fell 4 percent after Samsung Electronics Co. said it will spend $15 billion building a chip plant in South Korea. GT Advanced Technologies Inc. sank 93 percent after the company filed for bankruptcy. Hewlett-Packard Co. jumped 4.7 percent after saying it will split into two companies. CareFusion Corp. surged 23 percent as Becton, Dickinson & Co. agreed to buy the company for $12.2 billion.

The S&P 500 fell 0.2 percent to 1,964.84 at 4 p.m. in New York, erasing an earlier 0.5 percent gain. The Dow Jones Industrial Average retreated 17.72 points, or 0.1 percent, to 16,991.97. The Russell 2000 Index of small companies dropped 0.9 percent after the gauge capped its fifth straight weekly decline.

“We see stocks trading a little nervously today and this week before third-quarter earnings,” Jim Russell, a senior equity strategist at U.S. Bank Wealth Management in Cincinnati, said in a phone interview. “We’re anxious to see how company managements comment on the strong U.S. dollar and overseas revenue.”

Alcoa Inc. unofficially starts the U.S. earnings season on Oct. 8. Eight other S&P 500 companies will post results this week, including Yum! Brands Inc. and PepsiCo Inc. Profit at companies in the gauge rose 4.9 percent in the July-September period, according to the average estimate of analysts in a Bloomberg survey.

Strong Dollar

The S&P 500 climbed 1.1 percent on Oct. 3, paring a weekly decline, after data showed the U.S. jobless rate declined to a six-year low and employers hired more workers than economists had estimated. The dollar strengthened last week to a four-year high before weakening today.

Stocks tumbled last week amid signs of economic weakness in Europe and geopolitical turmoil as the Federal Reserve is on course to end its bond-buying program this month. Investors have been concerned the central bank may raise interest rates sooner than anticipated as the U.S. economy gains strength.

The Federal Open Market Committee releases minutes from its Sept. 16-17 meeting on Oct. 8.

Selling last week was heaviest among small-cap stocks, with the Russell 2000 sliding 1.3 percent. The fifth weekly drop was its longest streak since 2008. The gauge closed Oct. 1 more than 10 percent below its record from March, meeting the common definition of a correction, before rallying in the final two days of the week.

Apple Supplier

Losses today came as GT Advanced Technologies plunged 93 percent to less than $1. The maker of lab-grown sapphire used in mobile-device screens and parts supplier for Apple Inc. said it would continue operations during reorganization.

“That came as a big sucker punch out of the blue,” said Michael Block, chief equity strategist at Rhino Trading Partners LLC in New York. “It underscores how fragile any rally in the small caps is at this juncture. The small caps are behaving like frightened bunnies.”

About 6.3 billion shares changed hands on U.S. exchanges today, 9.4 percent below the three-month average. Last week saw the busiest trading in six months for U.S. equities, with an average 7.2 billion shares moving each day.

The Chicago Board Options Exchange Volatility Index rose 5.2 percent to 15.31 today. The gauge known as the VIX slid 2 percent last week.

Tax Preparer

Seven of the 10 main industries in the S&P 500 retreated today, with consumer-discretionary stocks sliding 0.6 percent for the biggest loss. Phone stocks jumped 0.4 percent to pace gains.

H&R Block Inc. fell 5.6 percent for the biggest decline in the S&P 500. The tax preparer said the sale of its banking unit to BofI Federal Bank is being slowed by a regulatory approval process. The firm had predicted the deal would close before tax season begins.

Micron Technology fell 4 percent and SanDisk Corp. dropped 2.7 percent after Samsung announced plans for the new chip factory.

Hewlett-Packard jumped 4.7 percent after announcing a split separating its corporate hardware and services operations, which will be led by current chief Meg Whitman, from the personal-computer and printer business. The latter will be led by Dion Weisler, currently vice president in charge of those operations.

CareFusion soared 23 percent. Becton, Dickinson agreed to pay $58 a share for the San Diego-based company that provides drug management and patient safety services to hospitals. That’s a 26 percent premium to its Oct. 3 closing price. Becton, Dickinson climbed 7.9 percent.

Durata Therapeutics Inc. rallied 75 percent as Actavis Plc announced a deal to acquire the maker of a skin-infection treatment.

To contact the reporter on this story: Oliver Renick in New York at orenick2@bloomberg.net

To contact the editors responsible for this story: Lynn Thomasson at lthomasson@bloomberg.net Jeremy Herron