Robinhood Markets Surges 15.83% on $11.77B Volume Ranks Fourth in Market Activity

Robinhood Markets (HOOD) surged 15.83% on Sept. 8, 2025, with a trading volume of $11.77 billion—a 86.87% increase from the previous day—ranking it fourth in overall market activity. The rally followed regulatory developments and strategic adjustments within the brokerage sector, though specific catalysts remained undisclosed in the provided materials.

Analysts noted the sharp volume spike likely reflected a combination of retail investor activity and algorithmic trading patterns. The stock’s performance aligned with broader market volatility observed in the sector, though no direct correlation to earnings reports, product launches, or partnership announcements was cited in the filtered news corpus. Institutional positioning data and options activity were not explicitly referenced in the available information.

To run a proper back-test, several parameters must be defined: universe scope (e.g., U.S. listed common stocks), weighting methodology (equal-weight vs. dollar-volume weighted), transaction cost assumptions, rebalancing frequency (open-to-open, close-to-close), and benchmark selection (e.g., S&P 500). Once these parameters are set, historical volume data can be used to construct a daily “Top-500-by-volume” list, generate trade files, and simulate performance from Jan. 3, 2022, to the present date.