The Dow industrials and S&P 500 rallied to fresh highs, kicking off the second half of the year on a bullish note.The rally took the Dow just shy of 17000, which would be the next milestone in a more-than-five-year rally for stocks after their financial-crisis declines. While the market's march to records has many investors less enthusiastic about paying high prices, they remain generally positive on stocks, thanks to expectations interest rates will stay low and the U.S. economy is growing modestly. The Dow Jones Industrial Average rose 129.47 points, or 0.8%, to a record 16956.07, after also notching a record intraday high of 16998.70. Tuesday's close marked the 12th record for the Dow this year, and it leaves the 30-stock index of blue chips up 2.3% for 2014. The S&P 500 index added 13.09 points, or 0.7%, to 1973.32, with the widely followed benchmark chalking up its 23rd record close of the year. The broader S&P has fared better than the Dow, gaining 6.8% in 2014. The Nasdaq Composite Index, meanwhile, gained 50.47 points, or 1.1%, to 4458.65. Traders said there was no particular news behind Tuesday's rally. As the bull market rolls on into the summer, steady flows of money into stocks and an absence of economic or political crises are creating a slow push higher, said Joseph Spinelli, head of Americas single-stock trading at Deutsche Bank AG DBK.XE +0.16% . "That will go on until you get some kind of shock to the system." Reflecting that pace, the S&P hasn't closed up or down more than 1% since April 16. At its peak Tuesday afternoon, the S&P was up 0.9% before falling back. Volumes have been low, as well. On Tuesday, about 6.1 billion shares were bought and sold, below the 2014 average of 6.4 billion. During June, an average of 5.6 billion shares a day changed hands in the U.S. To some extent, shares' rise likely reflects a continued trickle of investor cash into stock-focused mutual funds, said Tom Carter, managing director at brokerage firm JonesTrading Institutional Services LLC. Mr. Carter has seen managers buying existing names in their portfolios and adding new stocks, but buyers have been "patient," he said. "They may just be saying: 'You know what? This thing's going higher. We better be investing,' " he added. "If you're waiting for some sort of correction or repricing of the market, it hasn't happened yet. And, in the meantime, you're missing out on gains." To some money managers, stocks' prospects for later this year depend on how the coming second-quarter earnings season shakes out. The S&P 500's 30% rally in 2013 left many companies' shares on the pricey side of long-term averages, relative to their profits. The S&P 500 is trading at a price/earnings ratio of 15.6, according to FactSet. "It's really going to be earnings growth that propels the market higher," said Wayne Lin, a portfolio manager at QS Investors, which manages $14 billion. Investors also are looking ahead to the monthly employment report, to be released Thursday. Economists expect the Labor Department's nonfarm payrolls to show U.S. employers added 215,000 jobs in June. The report comes a day earlier in the week than usual, as the U.S. stock market will be closed Friday for the Fourth of July. Trading will end early Thursday ahead of the holiday. Tuesday, shares of fast-growing technology and health-care firms outperformed. Voxeljet VJET -6.80% climbed $4.96, or 24%, to $25.90, pacing a rally in 3D-printer makers' shares. Netflix, NFLX -0.85% whose stock has more than doubled the past year, added 32.50, or 7.4%, to 473.10, after Goldman Sachs GS +0.06% raised its rating on the stock to "buy" from "neutral." The Nasdaq Biotechnology Index gained 2.3%. European markets rose, with the Stoxx Europe 600 up 0.9%. Selling in safe-harbor bonds pushed the 10-year Treasury note's yield—which moves inversely to its price—up to 2.563%. Crude-oil futures declined less than 0.1% to settle at $105.34 a barrel. Gold futures gained 0.3% to $1,326.40 an ounce. Elsewhere in the corporate arena, shares of General Motors GM +0.43% rose 1.29, or 3.6%, to 37.59 after the auto maker reported a 1% increase in June auto sales, topping forecasts for a decline from researchers Kelley Blue Book and Edmunds.com. The report followed GM's recall of about 29 million cars and trucks in North America this year. Medical-device company Cooper COO -0.26% gained 11.42, or 8.4%, to 146.95, after announcing it agreed to buy privately owned contact-lens manufacturer Sauflon Pharmaceuticals for about $1.2 billion..