Wall Street's main indexes ended lower on Wednesday as talks between the White House and Republican representatives on raising the U.S. debt ceiling dragged on without a deal. The lack of progress on raising the U.S. government's $31.4 trillion debt limit ahead of a June 1 deadline, with several rounds of inconclusive talks, has made investors edgier as the risk of a catastrophic default looms larger. Winthrop Capital Markets chief portfolio manager Adam Coons spoke about the market and what investors should know.