Behind declines for shares of Dow Inc. and American Express, the Dow Jones Industrial Average is falling Tuesday afternoon. The Dow (DOW:DJIA) was most recently trading 152 points (0.6%) lower, as shares of Dow Inc. (NYS:DOW) and American Express (NYS:AXP) are contributing to the index's intraday decline. Dow Inc.'s shares have fallen $2.45, or 5.4%, while those of American Express have declined $2.83 (2.3%), combining for an approximately 36-point drag on the Dow. UnitedHealth (NYS:UNH) , IBM (NYS:IBM) , and Pfizer (NYS:PFE) are also contributing significantly to the decline. A $1 move in any one of the 30 components of the index equates to a 6.78-point swing.