Shares of Walgreens Boots and Dow Inc. are trading higher Wednesday afternoon, sending the Dow Jones Industrial Average into positive territory. The Dow was most recently trading 72 points, or 0.2%, higher, as shares of Walgreens Boots and Dow Inc. have contributed to the blue-chip gauge’s intraday rally. Walgreens Boots’s shares are up $1.32, or 2.6%, while those of Dow Inc. are up $1.45 (2.6%), combining for a roughly 18-point boost for the Dow. American Express UnitedHealth and Chevron are also contributing significantly to the gain. A $1 move in any one of the 30 components of the index equates to a 6.58-point swing.