U.S. stocks declined, after equities posted their best monthly gain since February, as commodities producers sank and Apple Inc. fell into a correction.

The Standard & Poor 500 Index retreated 0.3 percent to 2,097.97 at 4 p.m. in New York, after falling as much as 0.8 percent, to close above its average price during the past 100 days.

Commodities dropped after an official gauge of Chinese manufacturing slid to a five-month low and Iran said it will be able to bolster crude production within a week of sanctions ending.

The slide in equities accelerated Monday after the S&P 500 fell below its average price for the past 100 days, a level commonly watched by market technicians. The gauge last dropped below the 100-day moving average on July 24 during its longest losing streak since January. The S&P 500 is about 1.3 percent above its 200-day average, a level that has stopped the last two declines of more than 2.8 percent.

Apple fell for the ninth time in 10 days, sliding below its average price for the past 200 days for the first time since 2013 and extending its slide from a February high past 10 percent.

Source : Bloomberg