UnitedHealth Group (NYSE: UNH) shares are showing signs of life after months of punishing declines, with the stock climbing in pre-market trading on September 9.Shares were up about 4% in early action, trading at $332.10 before the opening bell, compared to the prior close of$320.25.UNH stock one-day stock price chart. Source: Google FinboldThe rebound comes as the health insurance giant reaffirmed its 2025 adjusted earnings per share guidance. The company also filed documents estimating that roughly 78% o ...