U.S. stock indexes skidded lower into Tuesday's close, amid negative headlines on Brexit and reports related to President Donald Trump's impeachment inquiry. The Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA +0.80% closed nearly 40 points, or 0.2%, lower at 26,788, with a post-earnings skid for shares of Travelers Cos. Inc. /zigman2/quotes/206313935/composite TRV -0.28% , off $11.76, or 8.3%, and McDonald's Corp. /zigman2/quotes/203508018/composite MCD -0.02% , down $10.58, or 5%, combining to deliver a 151-put headwind to the blue-chip index. Meanwhile, the S&P 500 index /zigman2/quotes/210599714/realtime SPX +0.77% closed down 0.4% at 2,996, slipping below a psychologically significant level at 3,000, while the Nasdaq Composite Index /zigman2/quotes/210598365/realtime COMP +0.73% finished 0.7% lower at 8,104. All closing levels are on a preliminary basis. The Wall Street Journal and others reported that U.S. diplomat Kurt Volker told the Ukrainian president he needed to convince Trump he was willing to investigate corruption and alleged Ukrainian 2016 election interference against former Vice President Joe Biden and his son, said the paper, citing people familiar with the former envoy's recent testimony to Congress. The disclosures may intensify the Congressional investigation into allegations that Trump withheld federal funds in exchange for a probe into a political rival. Separately, investors focused on on Brexit after U.K. lawmakers endorsed Prime Minister Boris Johnson's plan to leave the EU but voted against a fast-track plan that would have seen the country leave the trade bloc by Oct. 31, increasing some uncertainty around Brexit.