Even though the Chinese economy has been weakening for some time now, and oil prices have been tumbling for a good deal longer than that, with nothing else to worry about today Wall Street's focus turned once again to both of these issues dragging the Dow down another 91 points.  (At least no one seems concerned about Greece anymore.)  Who says the markets already have all this stuff factored in?  It seems pretty consistent that in the absence of fresh good news, very old news always resurfaces.  Volume was in line with recent averages at 6.5 billion shares.

Oops, did I say Greece was no longer on the radar?  Some late breaking bad news may indeed be hitting the markets hard tomorrow:
Greek stocks plunge, banks hammered, after five-week crisis shut down | Reuters

Mon Aug 3, 2015 4:40pm EDT

Weak oil prices, China worries drag Wall Street lower

BY NOEL RANDEWICH

DJ:     17,598.20  -91.66       NAS:      5,115.38  -12.90        S&P:      2,098.04  -5.80

REUTERS/ANTONIO ARAUJO

Wall Street ended lower on Monday as tumbling oil prices dragged energy shares to a three-year low and factory data from China raised concerns about the world's second-biggest economy.

Energy stocks were the biggest losers among the main S&P sectors. Exxon Mobil (XOM.N) and Chevron (CVX.N), which reported poor results on Friday, led the losses.

Oil prices fell on fresh evidence of growing oversupply and data highlighting slowing demand in China. Crude prices are on course for their weakest third-quarter performance since the financial crisis in 2008. [O/R]

In the United States, consumer spending recorded its smallest gain in four months, while the pace of growth in the manufacturing sector slowed in July.

China's factory activity shrank more than initially estimated last month, a survey showed. Concerns about China's economy hurt U.S. industrial stocks as well as Apple (AAPL.O), which relies on that country for much of its iPhone sales.

A report from market research firm Canalys showed Apple lost some smart phone market share in China in the second quarter. Its stock fell 2.36 percent, weighing most on the Nasdaq and the S&P 500.

The company's shares slipped below their 200-day daily moving average, a key technical level closely watched by traders, for the first time in nearly two years.

"It's a combination of the energy stocks, then the industrials and now the tech stocks, which have joined on the downside," said Donald Selkin, chief market strategist at National Securities in New York, which has about $3 billion in assets under management.

The Dow Jones industrial average .DJI fell 0.52 percent to end at 17,598.2. The S&P 500.SPX lost 0.28 percent to 2,098.04 and the Nasdaq Composite .IXIC dropped 0.25 percent to 5,115.38.

Half of the 10 major S&P sectors were lower, with the energy index .SPNY falling 2.01 percent to its lowest level since 2012.

After the bell, shares of Tenet Healthcare (THC.N) rose 2.3 percent as the company's second-quarter report pleased investors.

Tyson Foods (TSN.N) shares fell 9.9 percent during Monday's session after the biggest U.S. meat processor cut its profit forecast for the year, citing export market disruptions in its beef business and high cattle costs.

Peabody Energy (BTU.N) fell 9.17 percent as President Barack Obama prepared to unveil the final version of his plan to tackle greenhouse gases from coal-fired power plants.

Declining issues outnumbered advancing ones on the NYSE by a 1.54 to 1 ratio on the downside. On the Nasdaq, that ratio was 1.73 to 1 ratio favoring decliners.

The S&P 500 index posted 23 new 52-week highs and 26 new lows; the Nasdaq Composite posted 78 new highs and 141 new lows.

Some 6.5 billion shares changed hands on U.S. exchanges, below the five-day average of 7.1 billion this month, according to BATS Global Markets.