U.S. stocks staged a rally on Monday, buoyed by last week's comments by Janet Yellen, head of the Federal Reserve, who said the case for an interest rate rise "has strengthened in recent months," a sign of economic strength.

The S&P 500 increased 0.52%, the Dow Jones Industrial Average gained 0.59%, or 107.6 points, and the Nasdaq added 0.26%.

Yellen talked about a rate hike during her speech in Jackson Hole, Wyo., on Friday.

"I'm not surprised [Yellen] attempted to sound a little more hawkish," Ian Winer, head of equity trading at Wedbush Securities, based in Los Angeles, told TheStreet TV.

Fed Vice Chair Stanley Fischer, also on Friday, raised the prospect of a rates increase following the Fed's policy meeting next month. The central bank hiked interest rates for the first time since the 2008 recession in December 2015.

Financial stocks surged on Monday amid the expectations of higher interest rates. Wells Fargo (WFC) - Get Report added 2.2% and Bank of America (BAC) - Get Reportgained 0.4%. A rise in interest rates would boost the bank's profitability.

Personal income in the U.S. rose 0.4% in July, matching estimates. Consumer spending gained 0.3%, also in line with estimates.

West Texas Intermediate crude, the U.S. benchmark for oil, settled lower by 1.39% on Monday to $46.98 a barrel.

Apple (AAPL) - Get Report shares were flat after announcing it will hold an event on Sept. 7. While Apple hasn't released details, reports suggested the company is set to introduce a new iPhone, perhaps the iPhone 7.

Mylan (MYL) - Get Report rose 0.44% after it said it would offer a generic version of the life-saving EpiPen. The company sparked a wave of controversy after raising the price of the drug last week by 400%. The generic version is said to be priced 50% less than the branded line.

Herbalife (HLF) - Get Report rose 4.5% after billionaire activist Carl Icahn reported late Friday he had acquired 2.3 million additional shares of the nutritional supplements company.

Swiss drug maker Roche (RHHBY) said Monday that the Food and Drug Administration passed an Emergency Use Authorization for its Zika rRT-PCR test, which the company said helps detect the virus. Zika, which made landfall in the Miami area recently, has been linked to birth defects.

Carlyle (CG) - Get Reportis deciding if it should end its hedge fund business, according to a Financial Times report. One of its funds has lost some 90% of its value since 2014.

Harley Davidson (HOG) - Get Reportshares slipped 0.46% after Longbow analysts downgraded the stock to underperform from neutral amid a lack of upside catalysts in the near term.

Shares of capital equipment company KLA-Tencor (KLAC) - Get Reportrose 1.79% after Cowen analysts upgraded the stock to outperform from "market perform" with an $80 price target. The stock trades near $68.71.

Caesars Entertainment (CZR) - Get Reportshares slumped 15.67% after a judge ruled the company "must face lawsuits from bondholders," according to Reuters.

Starbucks (SBUX) - Get Report said it will open its first location in Trinidad, an island in the Caribbean. Starbucks first entered the region with its launch of a cafe in San Juan, Puerto Rico, back in 2002. Shares fell nearly 1%.

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