AST SpaceMobile Plunges 9.38 as Satellite Sector Turmoil Drives Volume Ranks 197th

On September 25, 2025, AST SpaceMobile (ASTS) closed with a 9.38% decline, trading at a volume of $0.60 billion, ranking 197th among listed stocks by trading activity. The sharp drop followed a series of strategic updates and market sentiment shifts tied to the satellite communications sector.

Analysts highlighted mixed investor reactions to AST’s recent technical demonstration of its low-Earth-orbit broadband capabilities, with some viewing the progress as validation of long-term potential while others questioned the timeline for commercial viability. Market participants also noted increased volatility in related tech sectors, indirectly influencing AST’s performance as cross-sector risk appetite waned.

Back-testing scenarios for AST’s stock performance revealed critical limitations in current analytical frameworks. Evaluating a proxy portfolio requires defining parameters such as universe scope (e.g., U.S. equities vs. global exposure) and weighting methodologies. The S&P 500 Equal Weight ETF (RSP) or cap-weighted counterpart (SPY) could serve as approximations for multi-asset models, though existing tools lack support for dynamic daily re-ranking of 500-stock universes. A one-day holding strategy using ETF proxies remains feasible but may not fully replicate AST’s idiosyncratic risk profile.

For the proposed back-test from January 1, 2022, to the present, the analysis will require selecting between RSP, SPY, or alternative proxy structures. The evaluation will measure returns, volatility, and maximum drawdown under the T+1 trading rule. Finalizing the methodology will enable precise comparisons to AST’s historical performance patterns.