* MSCI World Index eyes biggest weekly drop since February * Dollar up 0.1% at 9-1/2 month highs * Oil decline continues WASHINGTON/LONDON, Aug 20 (Reuters) - U.S. stocks ticked upward Friday in early trading while the dollar continued to post gains as a safe haven, as investors struggled to assess the impact of rising coronavirus cases, concerns over Chinese growth and the outlook for U.S. stimulus. The swirling economic currents have weighed on sentiment all week, setting a cautious tone ahead of a meeting of U.S. central bankers at Jackson Hole next week, with markets watching for any sign of monetary tightening in the world’s biggest economy. Wall Street opened Friday on an up note, with the Dow Jones Industrial Average climbing 0.2%, while the S&P 500 gained 0.25% and the Nasdaq Composite added 0.38%. “Markets continue to wrestle with a cauldron of concerns including inflation ... the Federal Reserve’s plans to taper its monthly bond-buying program and rising Covid cases,” said Art Hogan, chief market strategist at National Securities. “The natural instinct of some investors has been to lean into the negative narrative, and take profits,” Hogan said. The MSCI world equity index, which tracks shares in 45 nations, fell 0.05% as it flirted with its biggest weekly fall since February. The rise on Wall Street came after another sell-off in Asian markets, which saw their lowest close since November. MSCI’s broadest index of Asia-Pacific shares outside Japan was down 1.1% and 4.9% lower on the week, its weakest since February. Despite the market weakness, Mark Dowding, chief investment officer at BlueBay Asset Management, said abundant liquidity meant there was “plenty of cash that can buy the dip, so we doubt any correction in risk assets will run too far”. With cases of the Delta variant of coronavirus rising across the globe from the United States to Australia, safety was key and the dollar was a chief beneficiary. The dollar index, which measures its performance against six rivals, rose as high as 93.684 for the first time since early November, while gold also rose, up 0.2% and heading for its second straight week of gains. U.S. Treasury yields inched lower, with the benchmark 10-year yield at 1.2366%. Oil prices continued their downward slide seen throughout the week on travel demand concerns. U.S. crude was down 1.24% at $62.90 a barrel and Brent crude was down 1.3% at $65.58 per barrel. The commodity is down seven straight sessions and is facing a weekly loss of more than 7%. Additional reporting by Alun John; Editing by Catherine Evans and David Holmes Our Standards: The Thomson Reuters Trust Principles.