CDNA vs GH: 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. CDNA and GH 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 CDNA and GH 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.

CareDx builds and sells diagnostics, digital tools, and services for the organ-transplant community. Its core products are AlloSure, a next-generation-sequencing test that measures donor-derived cell-free DNA (dd-cfDNA) to detect kidney and heart transplant injury, and AlloMap, a long-established gene-expression test used by the large majority of U.S. heart-transplant centers. Around these tests the company layers patient-management software, pharmacy services, and a research-and-products franchise, positioning itself as an integrated transplant platform rather than a single-test lab.

Full CDNA guide

Guardant Health is a precision-oncology company that reads cancer signals from blood and tissue samples. Its business runs across three lines. Oncology, the largest, sells tests like Guardant360 (comprehensive genomic profiling that helps match patients to targeted therapies) and Guardant Reveal (a blood test for minimal residual disease, meaning traces of cancer left after treatment). Biopharma and Data sells testing, companion-diagnostic development, and real-world data to drugmakers. Screening is the newest and most-watched line: Shield is the first blood test to win full FDA approval as a primary screening option for colorectal cancer in average-risk adults 45 and older. In Q1 2026 the company reported ~$302 million in revenue, with oncology up 36% to ~$205 million on ~86,000 tests, biopharma and data at ~$53 million, and screening at ~$41.6 million on ~44,000 Shield tests (versus ~$5.7 million a year earlier).

Full GH guide

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

• CDNA drivers: Testing-volume growth; Return to profitability.
• GH drivers: Shield colorectal screening ramp; Core oncology growth and leverage.

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: Reimbursement is the central risk: bears flag potential headwinds of roughly $15 million to $30 million a year from possible coverage or coding changes, which would matter against a trailing revenue base near $458 million, although the recent Medicare coverage determination for allograft rejection testing has been read as favorable. For GH, guardant is unprofitable and cash-consumptive, so it depends on the Shield launch converting into durable, reimbursed volume rather than one-off wins.

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 CDNA if you believe its drivers more; GH 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 CDNA and GH guides.

CDNA. At $64.46 on October 16, 2026, CDNA trades at about 7.3 times trailing revenue, more than double the multiple of mid-2026, after the stock more than tripled this year. The trailing P/E of about 31 looks lower than the forward P/E of about 50 because trailing net income includes large non-operating gains; operating profit is near break-even. A cash pile of about $374 million with minimal debt gives flexibility, and reimbursement outcomes plus the October 29 Q3 report are the swing factors.

GH. Figures are approximate and tied to the asOf date; verify live numbers before acting. GH trades near 18 times trailing sales, a multiple typical of a fast-growing, pre-profit diagnostics company, so the valuation is driven by expected future growth rather than current earnings. The stock more than doubled over the year to October 2026 but sits about 17% below its 52-week high of about $191, and the November 5 report (consensus revenue ~$351 million) plus the pace of Shield adoption and the 2027 breakeven timeline matter more than any single quarter.

Headline figures (approximate, October 2026): CDNA shows revenue (ttm) ~$458M, revenue growth (q2 2026, yoy) ~52%, q2 2026 adj. eps vs est. $0.37 vs $0.23, gross / operating margin (ttm) ~71% / ~0%; GH shows revenue (ttm) ~$1.18 billion; Q2 2026 ~$335 million, up ~44% YoY, 2026 revenue outlook guided ~$1.30 to $1.32 billion earlier in 2026; consensus now ~$1.36 billion, gross margin (ttm) ~65%; operating margin ~-38%, net income (ttm) ~-$453 million loss; EPS ~-$3.50.

CDNA and GH 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 CDNA and GH exposure against your real portfolio. It is not an investment adviser.