NEW YORK (TheStreet) -- Stocks added to gains mid-afternoon Monday as investors processed a range of data from the ISM Manufacturing Index to U.S. personal income on what it might mean for the Federal Reserve's rate hike timeline.

The S&P 500 was up 0.47%, the Dow Jones Industrial Average added 0.44%, and the Nasdaq gained 0.47%. The Volatility IndexI:VIX, otherwise known as the "fear index," trimmed gains after jumping more than 4% earlier.

The technology sector was the best performer on markets, led by Microsoft (MSFT) - Get Microsoft Corporation (MSFT) Report and Altera (ALTR) - Get Altair Engineering Inc. Class A Report. Microsoft added 1.5%, caught up in a broader tech rally. The tech giant announced it will release its new operating system, Windows 10, on July 29. 

Altera jumped after Intel (INTC) - Get Intel Corporation (INTC) Report announced it was buying the chipmaker for $54 a share, or $16.7 billion in cash. Intel fell 1.7%, the worst performer on the Dow, while Altera climbed nearly 6%. Click here for more.

GoPro (GPRO) - Get GoPro, Inc. Class A Report rallied as the action camera maker announced the availability of its new Hero+ LCD camera, which is $100 less than its Hero4Silver model. The camera includes a touch display and a new in-camera video trimming feature. Click here for more.

The ISM Manufacturing Index increased to 52.8 in May from 51.5 in April, above estimates of 51.8. That marked its highest level since February. Separately, construction spending increased 2.2% compared to an expected 0.7% gain.

"This was a very strong ISM manufacturing sector report, and it comes at a time when doubts about the rebound in economic growth momentum are beginning to surface," said Millan Mulraine, U.S. strategist at TD Securities. "For the Fed, this report should do little to change the dynamics at the next meeting later this month, and we continue to see September as the earliest possible time for the Fed to get the necessary confirmation in the recovery to justify raising rates."

Boston Fed President Eric Rosengren isn't so confident in a rate hike sooner than later. Sluggish growth since winter means the conditions for a rate hike have not been met, he said in a speech on Monday. Rosengren is a non-voting central bank member this year.

"The data were not just weak during the worst of winter; they were also weak before the storms and have been weaker than expected ever since," Rosengren told a business group in Hartford, Conn. "This, in my view, makes a compelling argument for continued patience in monetary policy."

U.S. personal income in April increased 0.4% after a flat reading a month earlier. Economists had expected the measure to tick up 0.3%. Personal spending remained flat, as expected, after a revised 0.5% increase in March.

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"The April income and spending figures are another reminder that even though their incomes are rising at a healthy pace, households are still reluctant to boost spending more freely," said Paul Ashworth, chief U.S. economist at Capital Economics.

The focus this week will be on economic data, culminating in Friday's closely watched jobs numbers. Economists hope to see continued strength in the labor market, proof that March's disappointing number was an aberration in a weak first quarter.

Expectations are for the U.S. to have added 210,000 jobs in May with the unemployment rate remaining unchanged at 5.4%. Hourly earnings are forecast to increase 0.2% month on month.

Aside from Friday's jobs report, April factory orders will be released Tuesday, and the trade balance for April will be released Wednesday. The Fed's Beige Book, an anecdotal report of the 12 Federal Reserve districts, will be released on Wednesday afternoon.

Walt Disney (DIS) - Get Walt Disney Company Report shares were among the best performers on the Dow after Chief Financial Officer James Rasulo stepped down, effective June 30. A new finance chief will be named at a later date with Rasulo to stay on board long enough to assist with the transition.

SINA (SINA) - Get SINA Corp. Report surged after the Chinese media company announced its Chairman and CEO Charles Chao would purchase 11 million shares in a transaction valued at $456 million.

OM Group (OMG) rocketed 28.2% higher after funds managed by affiliates of Apollo Group (APO) - Get Apollo Global Management Inc. Class A Report agreed to purchase the specialty chemicals developer for $34 a share, 28% higher than Friday's close. Apollo plans to spin off OM's electronic chemicals and photomasks units to Platform Specialty Products (PAH) - Get Element Solutions, Inc. Report for $365 million in cash.

Citigroup (C) - Get Citigroup Inc. Report shares were on watch on reports the bank could close its Banamex USA unit after federal authorities announced an investigation into possible money laundering violations. Regulators reportedly want the unit to pay more than $100 million to settle allegations, according to Reuters.

Four clinical trials involving the checkpoint inhibitors from Merck (MRK) - Get Merck & Co., Inc. (MRK) Report and Bristol-Myers Squibb (BMY) - Get Bristol-Myers Squibb Company Report showed promising signs of efficacy in a wide range of solid tumors. Bristol-Myers shares were 3.2% higher. Click here for more.

Lumber Liquidators (LL) - Get Lumber Liquidators Holdings, Inc. Report shares were on watch after the company responded to inquiries as to why it relabeled certain engineered hardwood flooring products. The company said it did so because a supplier mislabeled some California Air Resources Board compliance numbers on some products, though said they remained CARB Phase II compliant.

Stocks closed Friday's session lower after a downward first-quarter GDP revision pressured markets. Benchmark indexes, however, notched a gain for May. Click here for more.