Stocks were mixed on Monday as the S&P 500 and Dow Jones Industrial Average wrapped up their best August performances since the 1980s. The Dow slid 223 points, or -0.8%, to 28,430.05 and the S&P 500 dipped -0.2% to close at 3,500. Meanwhile, the Nasdaq got a lift after two big stock splits took effect Monday. Apple shares gained 3.4% as a 4-for-1 split took effect. Tesla shares added 12.6% following its 5-for-1 split. Since announcing plans for the stock split on July 30, Apple has risen 35%, in the process becoming the first U.S. public company to surpass $2 trillion in market value and extending its gains for the year to 78%. Tesla shares, meanwhile, have surged 77% from the company's Aug. 11 stock-split announcement and have more than quintupled this year.