Powered by strong returns for shares of UnitedHealth and Visa, the Dow Jones Industrial Average is trading up Wednesday afternoon. The Dow /zigman2/quotes/210598065/realtime DJIA -3.15% is trading 77 points, or 0.3%, higher, as shares of UnitedHealth /zigman2/quotes/210453738/composite UNH -5.18% and Visa /zigman2/quotes/203660239/composite V -5.23% have contributed around 25% of the index's intraday rally. UnitedHealth's shares have risen $8.23 (2.9%) while those of Visa have gained $3.63 (1.9%), combining for an approximately 80-point bump for the Dow. Also contributing significantly to the gain are Merck /zigman2/quotes/209956077/composite MRK -1.30% , Coca-Cola /zigman2/quotes/209159848/composite KO -1.42% , and Pfizer /zigman2/quotes/202877789/composite PFE -2.13% . A $1 move in any one of the 30 components of the Dow equates to a 6.78-point swing.