McKesson Shares Plunge 1.16 as $370M Volume Slumps to 268th in U.S. Rankings

McKesson (MCK) closed on September 12, 2025, , , . . equities, reflecting subdued investor activity. The move followed a review of strategic testing parameters, which highlighted limitations in assessing multi-stock portfolio dynamics.

Analysts noted that the volume contraction suggests reduced short-term trading interest, though no direct catalysts were identified in the provided data. The absence of broader market news or sector-specific events left the decline unanchored to external factors, emphasizing the need for further context on operational or macroeconomic triggers.

Regarding back-testing constraints, the current system evaluates single tickers or predefined indices, limiting the ability to model strategies involving dynamic 500-stock portfolios. Alternative approaches include using liquidity-focused ETFs or refining the scope to individual tickers like SPY or QQQ. An event-driven analysis—such as tracking performance when a stock appears in high-volume lists—remains feasible but requires clarifying the specific methodology.