UnitedHealth Group shares edged higher on the New York Stock Exchange on Thursday, closing at $426.09 — up 0.64% on the day — as trading volume swelled to 10.7 million shares, roughly 1.6 times the 20-day average. The move looks small. The context is not. The largest U.S. health insurer has climbed 6.65% over the past month, extending a recovery from its three-month low of $320.12, and the latest session’s heavy participation suggests institutional money is re-engaging rather than drifting away. The question now is whether buyers have enough momentum to punch through the…