Behind negative returns for shares of American Express and Microsoft, the Dow Jones Industrial Average is falling Tuesday afternoon. Shares of American Express AXP, -2.40% and Microsoft MSFT, -0.42% have contributed to the index’s intraday decline, as the Dow DJIA, -0.12% was most recently trading 124 points (0.4%) lower. American Express’s shares are down $4.06, or 2.5%, while those of Microsoft have fallen $4.15 (1.5%), combining for a roughly 54-point drag on the Dow. Apple AAPL, -0.40%, UnitedHealth UNH, -1.93%, and Merck MRK, -1.31% are also contributing significantly to the decline. A $1 move in any of the index’s 30 components results in a 6.59-point swing.