NEW YORK, July 1 (Reuters) - The S&P 500 reached its sixth consecutive all-time closing high on Thursday, as a new quarter and the second half of the year began with upbeat economic data and a broad-based rally. Investors now eye Friday"s much-anticipated employment report. The bellwether index is enjoying its longest winning streak since early February, and the last time it logged six straight all-time highs was last August. "Historical data shows if you have a strong first half, the second half of the year was actually going even stronger," said Ross Mayfield, investment strategy analyst with Baird Private Wealth. The blue-chip Dow joined the S&P in positive territory, but a decline in tech shares - led by microchips - tempered the Nasdaq"s gain. "For markets so far this year, boring is beautiful," said David Carter, chief investment officer at Lenox Wealth Advisors in New York. "Economic growth has been strong enough to support prices and many asset classes are trading with historically low volatility." "It feels like investors left for the Fourth of July weekend about three months ago." The ongoing worker shortage, attributed to federal emergency unemployment benefits, a childcare shortage and lingering pandemic fears, was a common theme in the day"s economic data. Jobless claims continued their downward trajectory according to the Labor Department, touching their lowest level since the pandemic shutdown, and a report from Challenger, Gray & Christmas showed planned layoffs by U.S. firms were down 88% from last year, hitting a 21-year low. read more Activity at U.S. factories expanded at a slightly decelerated pace in June, according to the Institute for Supply Management"s (ISM) purchasing managers" index (PMI), with the employment component dipping into contraction for the first time since November. The prices paid index, driven higher by the current demand/supply imbalance, soared to its highest level since 1979, according to ISM. "The employment and manufacturing data released today supported the idea of continued growth but at a decelerated rate," Carter added. Friday"s hotly anticipated jobs report is expected to show payrolls growing by 700,000 and unemployment inching down to 5.7%. A robust upside surprise could lead the U.S. Federal Reserve to adjust its timetable for tapering its securities purchases and raising key interest rates. "Too-strong economic data could perversely be a bad thing for markets if it caused the Fed to raise rates faster than expected," Carter said. "Weak employment data may actually be welcomed." After Friday"s jobs data, the equity market"s next likely catalyst will be second-quarter earnings season set to commence in the coming weeks. Unofficially, the Dow Jones Industrial Average (.DJI) rose 125.8 points, or 0.36%, to 34,628.31, the S&P 500 (.SPX) gained 22.03 points, or 0.51%, to 4,319.53 and the Nasdaq Composite (.IXIC) added 18.44 points, or 0.13%, to 14,522.39. Walgreens Boots Alliance Inc (WBA.O) dropped after it said it expects to administer fewer COVID-19 vaccine shots in the fourth quarter. read more Didi Global Inc (DIDI.N) surged on its second day of trading as a U.S.-listed company. read more Micron Technology Inc (MU.O) lost ground following a report that Texas Instruments (TXN.O) would buy Micron"s Lehi, Utah, factory for $900 million. read more MGM Resorts International (MGM.N) advanced on the heels of its announcement that it will buy the remaining 50% stake in its JV, CityCenter Holdings LLC, for $2.125 billion from Infinity World Development.