2 Under-the-Radar Biotech Stocks Worth Buying for the Long Term

Mirum reported 2025 revenue of $521.3 million, up 54%, with Livmarli sales rising 69% to $360 million, and guided 2026 product sales to $630 million-$650 million. Vertex posted record 2025 revenue of $12 billion, up 9%, with 2026 sales guidance of $12.95 billion-$13.1 billion and FDA label expansion covering 95% of U.S. cystic fibrosis patients. The article is constructive on both stocks, citing Mirum's pipeline and Bluejay acquisition, and Vertex's expanded CF dominance plus non-CF growth opportunities.

Analysis

VRTX is the lower-volatility compounding story, but the key market mispricing is not the CF franchise itself; it is the duration of excess cash flow it creates for optionality. The label broadening meaningfully reduces the probability of a near-term step-down in the core cash engine, which in turn raises the value of every pipeline asset because management can fund launches and late-stage trials without equity dilution or balance-sheet stress. The second-order effect is that VRTX’s non-CF assets no longer need to win immediately to matter; they only need to show credible line-of-sight to a multi-year revenue ramp, which improves the asymmetry on any positive data in the next two quarters.

MIRM is a much cleaner catalyst-driven setup, but also the more fragile one. The market is likely underestimating how much of the next 12-18 months is now binary on readouts: the stock can re-rate quickly if HDV data validates a new multi-specialty platform, yet the downside if one of the key studies disappoints is severe because the current sales base is not large enough to absorb a pipeline reset. The Bluejay deal improves strategic coherence, but it also raises execution risk: integration + clinical dependence can compress the margin for error if launch cadence or trial timing slips.

The contrarian angle is that both names look better on a five-year spreadsheet than on a 6-12 month trading horizon. VRTX’s biggest risk is not competition but expectations: once CF is treated as a utility-like annuity, upside depends on evidence that non-CF can actually move from 'promising' to 'material' faster than the market currently prices. For MIRM, the consensus may be too focused on addressable market size and not enough on regulatory, safety, and payer friction in ultra-rare hepatology, where even strong data can take longer than expected to convert into durable revenue.

Key Decisions for Investors

• Long VRTX on a 6-12 month horizon; treat it as a quality-growth compounder with downside protected by the CF moat and upside from any credible non-CF contribution. Best entry on post-rally consolidation; target 15-20% upside with lower drawdown than the average biotech.
• Long MIRM only as a catalyst trade into the next 1-2 readouts, not as a full-size core holding. Use smaller sizing because the setup is asymmetric but binary; target a 25-35% move on positive data, with stop discipline around trial dates.
• Pair trade: long VRTX / short a basket of non-profitable biotech names with no near-term data catalysts. The thesis is that capital will reward balance-sheet strength and self-funding platforms while speculative biotech remains vulnerable to funding and trial-risk repricing.
• Buy MIRM calls or a call spread into the expected readout window rather than common stock if seeking defined risk. The optionality is better than paying full equity downside for a catalyst that may take months to convert.
• If VRTX rallies into optimism around non-CF expansion, trim and reload on any weakness rather than chase strength. The core cash engine is steady, so the best risk/reward is usually on pullbacks, not breakouts.