CINCINNATI--(BUSINESS WIRE)--U.S. consumers have driven Walmart's grocery penetration to a record 72% as financial insecurity among Americans ages 18–54 climbs to 70%, according to Wave 12 of the dunnhumby Consumer Trends Tracker (CTT) released today. Walmart serves over 190 million Americans monthly—2.5 times the reach of second-place Dollar General at 28.6%. Walmart's penetration rose 6 percentage points (pp) year over year, marking the largest growth in penetration among all retailers. The q. ...