Here are the most important news, trends and analysis that investors need to start their trading day:1. Wall Street tracks lower after a bright spot in a tough monthPeople walk by the New York Stock Exchange, August 9, 2021.Andrew Kelly | ReutersU.S. stock futures dipped Thursday ahead of retail sales and weekly jobless claims data, released at 8:30 a.m. ET. The Dow Jones Industrial Average and S&P 500 on Wednesday rallied for their second gain in the past eight sessions. The Nasdaq broke a five-session losing streak. Ahead of Thursday’s open on Wall Street, the Dow, S&P 500 and Nasdaq were all down during the historically rough month of September. The Dow was 2.3% away from its Aug. 16 closing record. The S&P 500 was more than 1.2% away from its Sept. 2 closing record. The Nasdaq was 1.4% away from its Sept. 7 closing record.2. Investors to watch latest retail sales, weekly jobless claims dataEconomists expect August retail sales to drop 0.8% after falling 1.1% in July. Initial jobless claims for the week ending Sept. 11 are seen rising slightly to 320,000 from the prior week’s pandemic-era low of 310,000. Investors will look to Thursday’s data for signals on how the economy is weathering elevated Covid cases in the U.S. due to the spread of the delta variant and how that might figure into the Federal Reserve’s thoughts on when to start tapering bond purchases. Central bankers are set to hold their two-day September meeting next week.3. Much of September losses historically come in back of monthA screen shows Federal Reserve Chair Jerome Powell speak as a trader works inside a post on the floor of the New York Stock Exchange (NYSE), August 27, 2021.Brendan McDermid | ReutersThe Fed’s policy statement next Wednesday and Fed chief Jerome Powell’s news conference are wild cards during an already particularly weak period for stocks. Historically, the bulk of September’s losses come in the back half of the month. In fact, it appears the S&P 500 usually peaks around the 17th day of the month, which is this Friday. CNBC’s Jim Cramer and others on Wall Street have warned about this pattern. So far in September, the index was down nearly 1%. The Dow and Nasdaq, for the month, were down 1.5% and 0.6%, respectively.4. FDA strikes cautious tone ahead of vaccine booster meetingVials and a medical syringe seen displayed in front of the Food and Drug Administration (FDA) of the United States logo. FDA finds the COVID-19 vaccine.Pavlo Gonchar | LightRocket | Getty Images5. Southwest Airlines unveils new Covid vaccine incentives for staffA passenger aircraft operated by American Airlines Group Inc. lands at Miami International Airport in Miami, Florida, U.S., on Wednesday, June 16, 2021.Eva Marie Uzcategui | Bloomberg | Getty ImagesSouthwest Airlines has introduced new incentives to get staff vaccinated against Covid. The Dallas-based carrier will offer extra pay to workers who show proof of full vaccination by mid-November, according to a company memo, which was reviewed by CNBC. U.S. airlines have taken varying approaches to get staff vaccinated. United has required its roughly 67,000-person U.S. workforce to be vaccinated, saying it will put staff who receive religious exemptions on temporary unpaid leave. Delta Air Lines plans to charge unvaccinated employees $200 more per month for company health insurance starting in November.— The Associated Press contributed to this report. Follow all the market action like a pro on CNBC Pro. Get the latest on the pandemic with CNBC’s coronavirus coverage.