US stocks open lower as bond yields climb; Dow down 81.8 points

U.S. equities opened lower as a rebound in government bond yields tightened financial conditions and weighed on risk appetite. A rare Walmart sales miss added pressure by raising concerns about consumer demand and retail sector momentum. The early declines across the Dow, S&P 500, and Nasdaq highlight sensitivity to rate moves and earnings surprises, potentially increasing near-term index volatility and sector dispersion.