Amgen's 141st-Ranked Stock Volume Marks Fitch Rating Upgrade Amid Debt Cuts and Biosimilars Growth

Market Snapshot

Amgen’s stock (AMGN) edged up 0.03% on December 23, 2025, with a trading volume of $0.51 billion, marking a 35.65% decline from the previous day’s volume. This placed the stock at the 141st highest volume in the market, reflecting muted investor activity despite the modest price gain. The performance contrasts with broader market volatility, though the company’s shares showed resilience amid a decline in trading interest.

Key Drivers

Fitch Ratings’ recent upgrade of Amgen’s long-term issuer default rating to BBB+ from BBB underscored the biotechnology giant’s improved financial structure, a key catalyst for market confidence. The rating agency highlighted Amgen’s deleveraging efforts, including $10 billion in debt repayment since its 2023 acquisition of Horizon Therapeutics. This has reduced EBITDA leverage from 3.9x to 3.0x, aligning with Fitch’s projection of 4.8% compound annual revenue growth through 2028 and adjusted EBITDA margins of 47%-49%. The stable rating outlook reinforces Amgen’s strong profitability relative to peers like Bayer AG and Viatris Inc., positioning it as a resilient player in a sector grappling with pricing pressures and regulatory headwinds.

Amgen’s operational strength is further reflected in its diversified portfolio. The company reported 10% revenue growth and 14% volume growth in the first nine months of 2025, driven by double-digit gains in 12 products. Its rare disease franchise, nearing $5 billion in annual sales, and biosimilars business, contributing $3 billion annually, highlight its ability to balance innovation with established revenue streams. However, challenges loom: patent expirations for Prolia and XGEVA in 2025 threaten $6.6 billion in U.S. and European sales, while the Inflation Reduction Act and tax litigation risks could weigh on margins.

The GLP-1 agonists market report, though not directly tied to Amgen, underscores broader industry dynamics. With the semaglutide patent expiring in 2026, biosimilars are expected to gain traction, a segment where Amgen has a strategic foothold. Fitch noted that Amgen’s robust R&D pipeline, including regulatory approvals for IMDELLTRA and MariTide (a phase III obesity drug), could offset near-term headwinds. These advancements reinforce Amgen’s competitive positioning in immunology and oncology, areas critical for long-term growth.

A lingering risk remains the IRS dispute over 2010-2015 profit allocation, which seeks $10.7 billion in taxes, interest, and penalties. While Fitch acknowledges this as a “material but manageable” issue, a 2026 Tax Court ruling could introduce short-term uncertainty. Investors appear unfazed, however, as Amgen’s strong cash generation and disciplined capital allocation—evidenced by its focus on debt reduction—mitigate near-term rating implications. This financial prudence, combined with a stable outlook from Fitch, positions Amgen to navigate macroeconomic and sector-specific challenges while maintaining its status as a top-tier healthcare stock.