Let's check out the charts again.
In the daily bar chart of UNH, below, I can see that share prices stalled in late July and early August before turning lower again. They are now back below the declining 50-day moving average line and the declining 200-day moving average line.
The On-Balance-Volume (OBV) line shows weakness from late July and suggests that sellers of UNH have been more aggressive than buyers. The Moving Average Convergence Divergence (MACD) oscillator turned bearish again in late August.