Abbott Stock Falls 0.53% on Regulatory Uncertainty as $560M Volume Ranks 180th in U.S. Liquidity

, 2025, , ranking 180th among U.S. stocks by liquidity. The decline came amid mixed signals from regulatory updates and operational developments within the medical device sector.

Recent regulatory scrutiny over post-market surveillance requirements for certain cardiac rhythm management devices has created short-term uncertainty for Abbott. While the FDA has not issued direct penalties, analysts note the potential for prolonged compliance costs and delayed product approvals in 2026. This contrasts with positive momentum in Abbott's diabetes care division, where recent supply chain optimizations have stabilized insulin pump production.

Strategic shifts in the company’s diagnostics business also drew investor attention. Abbott announced plans to consolidate three underperforming lab testing facilities in Texas, redirecting capital toward . The move, , raises questions about long-term R&D investment allocation.

To run this back-test robustly I need to pin down a few implementation details and make sure the assumptions match what you have in mind: 1. Stock universe • Should I use all U.S-listed common stocks (≈ 3 000 names) as the starting universe each day, or do you want a different region/universe? 2. Ranking & trade timing • I plan to form the volume ranking at the close of each trading day, buy the top-500 names at that close, and exit all positions at the next day’s close (one-day holding period). • Does that match your intent, or would you prefer to trade at the next day’s open? 3. Weighting & capital allocation • Default would be equal-weight across the 500 names each day. • Any other weighting (e.g., , )? 4. Transaction costs & slippage • Unless you specify otherwise I will assume zero explicit transaction costs or slippage. 5. Benchmark (optional) • If you’d like the results compared with a benchmark index (e.g., SPY), let me know. Once I have these details (or your confirmation that the defaults above are acceptable) I can generate the data-retrieval plan and run the back-test.