Blood Simple

At a biotech conference in San Francisco a few years ago, I found myself seated next to a young, eager analyst from a mid-tier hedge fund. He asked me if I thought liquid biopsy was “a real thing” or just another Silicon Valley mirage. I told him to watch Guardant Health (GH).

If they cracked the code, we’d look back on blood-based diagnostics as the quiet revolution that changed everything about cancer care. He nodded politely and scribbled something into his notebook.

Guardant Health’s most recent quarter offers all the proof that we needed. Revenue jumped nearly 40% from last year, oncology testing volumes are climbing, and the company has lifted full-year guidance.

Their screening business has hit a $100 million run rate, and that’s before full distribution even begins.

Most of the attention has focused on the top-line numbers, but the more interesting story is what those numbers represent. They’re proof that Guardant has moved from promise to execution.

Sadly, too many investors still lump Guardant in with a crowded pack of diagnostics hopefuls. That misses the point.

What sets Guardant apart isn’t better tests but their growing control of the data layer that underpins modern oncology. With over a million patient samples now processed and a growing list of partnerships across pharma, Guardant is quietly building the connective tissue between diagnosis, monitoring, and treatment.

That’s what the Street hasn’t fully priced in yet.

The MRD business, driven by its Reveal test, is particularly promising. CRC surveillance has Medicare coverage, and reimbursement pathways are expanding into other tumor types. Guardant’s strategy here is methodical: build clinical evidence, win coverage, scale up volumes.

Screening, on the other hand, has drawn more scrutiny, especially after the Shield V2 data underwhelmed. The improvements in early-stage sensitivity were modest, and the market punished the stock accordingly.

But investors looking only at those results are missing the larger play. Guardant is laying the groundwork for broad adoption through its partnerships with Quest Diagnostics and PathGroup, which will push Shield into physician workflows nationwide starting early next year.

Inclusion in guidelines from the NCCN and ACS is on the horizon, and when those dominoes fall, payer adoption typically follows. Shield doesn’t need to be perfect today; it needs to be available, trusted, and improved over time. That’s how screening becomes a long-term contributor.

There are also early signs that Shield’s multi-cancer version could become an important pillar of the business. The specificity and positive predictive value from their early data are impressive. It won’t reach scale overnight, and reimbursement is still a few years away, but Guardant is positioning itself well.

Few other players have the distribution, data infrastructure, or regulatory experience to compete at this level.

On the technology front, InfinityAI is quietly doing the work of improving test accuracy and informing drug discovery. This isn’t a flashy story for most investors, but it matters.

The ability to integrate multi-omic data and iterate diagnostic tools based on real-world feedback gives Guardant a structural advantage. It’s also what’s drawing interest from pharma partners and could ultimately extend Guardant’s reach well beyond oncology.

Financially, the picture is improving. Oncology revenue rose 31% year-over-year, biopharma brought in another $55 million, and Shield screening contributed $24 million.

Gross margins are rising, and while free cash flow remains negative – mostly due to investment in the screening rollout – the core business is close to breakeven. Management believes screening can hit cash-flow break-even once it reaches $600 to $800 million in revenue.

Valuation has come up, but not excessively. The company trades in line with peers despite having stronger near-term growth and a more diversified pipeline. Risks remain: Shield must continue to improve, Reveal needs to prove its sensitivity across more cancers, and guideline inclusion isn’t guaranteed.

But the direction is clear, and Guardant has a track record of delivering. That’s more than can be said for many of its peers.

Back at that conference, as the sessions wrapped up and the wine started flowing, the young analyst circled back to our table. He said he’d looked into Guardant and wasn’t convinced — too speculative, he said. I smiled, nodded, and let it go.

Some lessons you can’t teach. You just have to live long enough to see them play out. If he’s still watching, Guardant’s latest numbers should offer a healthy dose of clarity.