It was a mixed close on Wall Street Wednesday as the Federal Reserve kept interest rates near zero.The Dow lost 127 points weighed down by earnings. The S&P 500 was little changed. The Nasdaq rallied 102 points.Fed chief Jerome Powell says the economic rebound continues to "strengthen," but wouldn’t give any timetable on when the Fed would pullback on the Fed’s extraordinary bond-buying program that’s been supporting the recovery."So it certainly is plausible that people would pull back from some activities because of the risk of infection. Dining out, traveling, some schools might not reopen. We may just see economic effects from some of that or it might weigh on the return to the labor market. Some people might choose - - again, we don't have a strong sense of how that might work out. So we'll just be monitoring it, monitoring it carefully."But, overall, Powell was upbeat, saying the U.S. is on the path to a strong labor market, and he remains confident inflation will eventually cool after its recent surge. Investors also had earnings to digest. After the close, Facebook beat estimates but warned revenue growth will “decelerate significantly” for the second-half of the year.Global sales at McDonald's surged 57% to just under $6 billion in the second quarter - reversing the 30 percent plunge a year ago. McDonald's had a winner with a meal named after the popular South Korean band BTS. The stock was down nearly two percent as investors hungered for even stronger results. Boeing posted a surprise quarterly profit as sales of its 737 MAX bounce back along with the upswing in U.S. domestic travel. Boeing finished the day with a more than 4-percent gain.Pfizer raised its full-year forecast due to strong sales of its vaccine, as well as its stable of drugs, sending its stock up more than 3 percent.And investors also had a high-profile IPO to digest. Duolingo, the popular foreign language app, soared 36 percent in its market debut.