CRSP vs RARE: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of October 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. CRSP and RARE share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined CRSP and RARE exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

CRISPR Therapeutics AG is a Swiss-American biopharmaceutical company headquartered in Zug, Switzerland, with principal research operations in Boston, Massachusetts. The company uses its proprietary CRISPR/Cas9 platform to develop gene-based medicines across hemoglobinopathies, oncology, cardiovascular disease, autoimmune conditions, and regenerative medicine. Its first and only commercialized product, Casgevy, is co-developed and co-commercialized with Vertex Pharmaceuticals under a 40/60 profit-sharing structure in which CRISPR retains 40 percent of profits. Revenue has historically been driven by collaboration milestone payments from Vertex rather than product sales, making the financial profile highly lumpy. Beyond Casgevy, the company generates no meaningful product revenue today and funds operations through its cash reserves.

Full CRSP guide

Ultragenyx Pharmaceutical (NASDAQ: RARE) develops and sells treatments for rare and ultra-rare genetic diseases, conditions with small patient populations and often no approved therapy. Its commercial base includes Crysvita for X-linked hypophosphatemia (its largest product), Dojolvi for long-chain fatty acid oxidation disorders, Evkeeza, and Mepsevii, which together produced about $673 million of revenue in 2025. The company spans multiple modalities, protein-replacement, small molecule, antisense, and gene therapy, and in 2026 turned two late-stage gene therapies into approved products: Genglycos (DTX401, pariglasgene brecaparvovec) received accelerated approval for glycogen storage disease type Ia in August 2026, and Fayuvi (UX111) was approved in September 2026 for the neurologic manifestations of Sanfilippo syndrome type A (MPS IIIA) in children with preserved neurodevelopmental function, the first FDA-approved treatment for that condition and the company's sixth FDA approval.

Full RARE guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• CRSP drivers: First-Mover Advantage in Commercial Gene Editing; Casgevy's Long-Term Revenue Potential.
• RARE drivers: New gene therapy launches; Angelman syndrome readout.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: The commercial ramp of Casgevy has been far slower than early projections: CRSP's reported revenue was only about $3.5 million in all of 2025, down sharply from prior years that were boosted by one-time milestone payments, and only about $13.4 million over the twelve months to June 2026. For RARE, ultragenyx remains unprofitable, with a net loss of about $586 million over the trailing twelve months and, per Yahoo Finance, about $292 million of cash against about $1.2 billion of debt as of June 30, 2026, so continued spending or slow launches could pressure the balance sheet and raise dilution or financing risk.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick CRSP if you believe its drivers more; RARE if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the CRSP and RARE guides.

CRSP. Because CRISPR Therapeutics has no meaningful product profits yet, traditional earnings-based multiples like P/E are negative and not analytically useful; the company is better evaluated on cash runway, Casgevy adoption, and the risk-adjusted value of its pipeline. Market cap of about $4.9 billion less roughly $1.6 billion of net cash leaves an enterprise value near $3.3 billion, which reflects significant execution uncertainty. Targets remain widely spread, from UBS at $52 to a consensus mean near $86.

RARE. Ultragenyx trades at about 2x trailing revenue, a low multiple for a biopharma with six approvals, and has no earnings, so conventional P/E valuation does not apply. The market is pricing the launch ramp of Genglycos and Fayuvi, the Angelman program, a heavy debt load and the credibility of the 2027 profitability goal. Analysts expect about $989 million of revenue in 2027 and a mean price target near $26 across 20 analysts, well above the share price.

Headline figures (approximate, October 2026): CRSP shows revenue (ttm to jun 30, 2026) ~$13.4 million (Q2 2026 ~$10.2 million), revenue (full year 2025) ~$3.5 million, net loss (ttm) ~$451 million; Q2 2026 ~$91 million, eps (q2 2026, actual vs estimate) -$0.94 vs -$1.18; RARE shows revenue (ttm) ~$717M (2026 guidance $730M-$760M, excluding launches), q2 2026 revenue ~$214M (first half 2026 ~$350M, up ~14%), q2 2026 eps ~-$0.90 vs ~-$1.00 expected (net loss ~$92M), net loss (ttm) ~$586M.

CRSP and RARE are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined CRSP and RARE exposure against your real portfolio. It is not an investment adviser.