U.S. stock index futures edged lower Wednesday night as market sentiment remained fragile amid growing concerns over high government debt and uncertainty surrounding President Donald Trumps proposed tax cut bill.

US stock futures showed little movement as markets digested the House passage of Trump’s tax bill, which could add $3.8 trillion to national debt. Investors remained cautious following a recent selloff triggered by rising Treasury yields and debt concerns.

Wall Street's main indexes opened lower on Wednesday, as investors awaited the outcome of a pivotal debate around U.S. President Donald Trump's tax-cut bill that has fanned concerns about the country's growing debt.