By The Associated Press___ Why worry? Less aid by Fed would point to recovery WASHINGTON (AP) â¿¿ Investors have grown nervous that the Federal Reserve will scale back its efforts to boost the U.S. economy sooner than many expected. Yet almost lost in the anxiety that gripped the stock market this week is that whenever the Fed slows its drive to keep interest rates low, it will be cause for celebration: It would mean policymakers think the economy is strong enough to accelerate with less help from the Fed. Over the past five years, the Fed has acted aggressively to try to boost the economy. Among other steps, it cut short-term interest rates to record lows and said it planned to keep them there at least until unemployment falls to 6.5 percent (from 7.5 percent in April). ___ Stocks edge lower as investors reassess Fed fears NEW YORK (AP) â¿¿ Investors recovered their poise after a shaky start to trading on Wall Street that sent stocks sharply lower. U.S. markets plummeted immediately after the opening bell Thursday following a global slump prompted in part by an unexpectedly weak report on manufacturing in China. Concern that the Federal Reserve might ease back on its economic stimulus program sooner than expected had also riled investors. The dip gave investors who had missed this year's rally in stocks an opportunity to get into the market, and by midday stocks had recouped most of their early losses. The market even climbed into positive territory by midday, before ending the day marginally lower. ___ Japan gyrations underline economy's vulnerability TOKYO (AP) â¿¿ Japan's financial markets gyrated wildly Thursday, underscoring the vulnerability of its economy to a loss of investor confidence as Prime Minister Shinzo Abe attempts shock monetary easing to end two decades of stagnation.