AJG Ranks 339th in $340M Volume as Stock Gains 0.71% Amid Insider Sale

On September 16, 2025, Arthur J. Gallagher & Co. , , ranking 339th in market activity. The stock’s performance followed a notable insider transaction involving Representative (D-Texas), . The sale occurred via her Chase Brokerage Account, reflecting a strategic move amid broader market volatility.

Johnson’s trade aligns with her across multiple sectors, including financial services, healthcare, and industrials. While insider sales often raise scrutiny, the absence of additional earnings or operational updates from AJG suggests the move was part of a rather than a direct response to company-specific news. The stock’s modest gain contrasts with broader sell-offs in tech and energy, indicating resilience in its insurance and niche.

Backtesting parameters for AJG’s performance require defining key variables: universe scope (e.g., S&P 500 vs. all U.S. stocks), trade execution timing (prior-day volume vs. intraday), portfolio weighting (equal-weight vs. volume-weighted), and exit rules (next-day close vs. open). Transaction costs and simplifications, such as tracking an equal-weight index, must also be specified. These choices will determine the accuracy of the backtest in reflecting real-world trading dynamics.