U.S. markets are closed for Labor Day on Sept. 5, but investors are looking ahead to a key European Central Bank policy meeting and quarterly results from a slew of major companies. The European Central Bank holds its September meeting and press conference on Thursday. While the ECB kept interest rates steady and didn't announce new stimulus measures at its last meeting in July, policy officials have alluded to possible stimulus measures announced at the September meeting, amid June's historic Brexit vote. As for U.S. economic developments, the Job Openings and Labor Turnover Survey for July is released Wednesday, along with the Fed's Beige Book. Weekly jobless claims are released on Thursday. On the earnings calendar, Dave & Buster's Entertainment (PLAY) reports on Tuesday. Wednesday, the markets await results from Hewlett Packard Enterprise (HPE) and Valspar Corporation (VAL) . On Thursday, Barnes & Noble (BKS) and Restoration Hardware (RH) release results, while The Kroger Company (KR) reports earnings on Friday. TheStreet's Scott Gamm reports from Wall Street.