Liquid biopsy's quiet bottleneck: who is building lab capacity first

The read: capacity is the story this quarter

Diagnostics and liquid biopsy get discussed as a demand story: more patients tested, more doctors ordering. The latest earnings calls from three companies point to a different constraint. Each one spent real airtime on the physical and digital capacity needed to process tests.

That matters because a test business is a factory business. Volume has to run through a lab, and the cost of each test decides how much of every dollar of revenue is kept. The companies that build capacity early, and bring cost per test down as they scale, are the ones worth understanding first.

Our score ranks BillionToOne first in this group, CareDx second and Guardant Health third. The rest of this piece uses what each company said on its Q2 FY2026 call to show why capacity sits at the centre of that picture.

BillionToOne: a dedicated lab, and a margin floor

BillionToOne is the lead name here. It sells prenatal tests and is building out oncology testing.^4,1 On its August 5, 2026 call, the company said it had signed a lease for a dedicated 62 thousand square foot oncology production lab.¹

The company expects that lab to support capacity of approximately 5 thousand tests per day over time.¹ The wording is a plan, not a result, and it is conditional on the lab being built out and filled. But a dedicated site tells you the company is planning for oncology volume to be large enough to justify its own production floor.

The prenatal side is where management expects growth to come first. The company expects significant growth in prenatal tests from several factors, including sales rep hiring and data readouts.⁴ More reps and more clinical data are demand levers, and the new lab is the supply that can absorb them.

Then there is margin. The company plans to manage the business to keep gross margins above 70% by raising average selling prices (ASPs, what is collected per test) and reducing cost of goods sold.⁵ Pairing a price lever with a cost lever is the right shape for a capacity build, because new labs usually weigh on margins before volume fills them.

Guardant Health: building ahead of volume, and cutting cost per test

Guardant Health is the clearest example of building capacity before it is needed. On its July 30, 2026 call, it said it is accelerating investments to continue building lab capacity ahead of rapidly increasing volume.³ It is also investing in lab automation and broader infrastructure to support higher test volumes.⁶

The cost side gives that spending a target. Guardant expects to reduce the cost per test of Shield, its screening product, by roughly 15% from the current level of approximately $410 by the end of 2026.² That is a company expectation, and the end-of-year figure is the checkpoint to watch.

Guardant also has a regulatory asset in oncology. It holds FDA approval for Guardant360 Liquid CDx, which carries 100x more content than its legacy FDA-approved CDx product.⁷ CDx here means a companion diagnostic, a test tied to deciding which patients get a given therapy. More content per approved test is a reason for ordering volume to rise, which is exactly what the new capacity is meant to serve.

CareDx: capacity in the workflow, not just the lab

CareDx shows that capacity is not only about square footage. The company works with transplant centers, and its call focused on how its testing connects to their systems.^8,9

CareDx has integrated electronic medical records (EMRs) for 50% of its test volume.⁹ It also expects to be live with 30 to 40 transplant centers using Epic Aura by the end of the year.⁸

Why does that belong in a capacity story? Orders that arrive electronically and results that return to the chart cut manual handling on each test. That frees up throughput in the same way a larger lab does. If those integrations go live as the company expects, they are a way of adding effective capacity without adding a building.

What ties the three together

Each company is working on the same equation from a different angle. BillionToOne is adding a physical site and holding a margin floor.^1,5 Guardant is adding lab capacity, automating it and driving cost per test lower.^3,2,6 CareDx is pushing orders and results through connected systems.^8,9

There is a useful signal in the commercial side too. BillionToOne said it has not seen payer friction due to intentional coding practices.¹⁰ Payers, the insurers that reimburse tests, can slow down a fast-growing test business. Capacity only turns into revenue if reimbursement keeps pace, so a clean read on that point supports the build-out.

The common risk is timing. Capacity is committed before the volume it is meant to serve, which is how Guardant describes its own approach.³ If volume arrives slower than the labs are built, the cost lands first and the benefit later.

What to watch next

Next quarter's calls offer clear checkpoints. For BillionToOne, watch for progress on the oncology lab and whether gross margin stays above the 70% level management says it is managing toward.^1,5 For Guardant, the marker is cost per test on Shield against the roughly 15% reduction expected by end of 2026.²

For CareDx, track how many transplant centers go live on Epic Aura against the 30 to 40 it expects by year-end, and whether the 50% EMR integration figure moves higher.^8,9

A simple way to read the group: demand gets the headlines, but cost per test, lab throughput and integrations show how much of that demand each company can serve at a good margin. Those are the numbers that will tell you whether the build-out is paying off.