AbbVie Shares Fall 0.68% with 99th-Ranked Volume Amid Regulatory Pressures

AbbVie (ABBV) closed on October 8, 2025, with a 0.68% decline, trading with a volume of 1.01 billion shares, ranking 99th in total trading activity across the U.S. equity market. The stock's performance followed a mixed regulatory landscape affecting its core therapeutic areas, including rheumatology and oncology. Analysts noted heightened sensitivity to near-term guidance adjustments as a key driver of short-term volatility.

Recent regulatory scrutiny on AbbVie’s drug pricing strategies intensified investor caution, with market participants recalibrating expectations for future revenue streams. The company’s pipeline updates during the quarter provided limited reassurance, as upcoming patent expirations for key products remain a looming overhang. Institutional positions showed reduced exposure in the preceding week, reflecting a broader risk-off sentiment amid sector-specific challenges.

To run this back-test in a way that is statistically sound—and also executable with the toolset we have—we need to pin down a few practical details. Please let me know your preferences on the points below (a quick numbered reply is fine):

1. Stock universe • All common stocks listed on NYSE + NASDAQ? • A narrower benchmark universe (e.g., Russell 1000 or S&P 1500)? • Something else?

2. Data-timing convention (to avoid look-ahead bias) • Select today’s “top 500 by volume” after the close, buy them at the next day’s open, sell at the same day’s close (1-day holding period). • Or buy at today’s close and sell at tomorrow’s close? • Another convention?

3. Trading frictions • Ignore transaction costs/slippage (pure gross return)? • Apply a per-trade cost (e.g., 5 bps per side)?

4. Tool limitation & possible workaround Our built-in back-test engine is single-ticker, so for a cross-sectional portfolio we have two options: a) I can generate and share the strategy logic (screen + portfolio construction) in detail for you to implement offline; b) Or I can approximate with a representative ETF / index (e.g., an equal-weight index proxy) if that meets your immediate need.

Once I have your answers, I’ll proceed (or suggest an alternate path) right away.