Thank you for standing by, and welcome to BillionToOne's Fourth Quarter and Full Year 2025 Earnings Conference Call. [Operator Instructions] I would now like to hand the call over to David Deuchler, Investor Relations. Please go ahead.

Good afternoon, everyone. Thank you for participating in today's conference call. Joining me on the call from BillionToOne, we have Oguzhan Atay, Co-Founder and Chief Executive Officer; and Ross Taylor, Chief Financial Officer. Earlier today, BillionToOne released financial results for the fourth quarter and full year ended December 31, 2025. A copy of the press release is available on the company's website. Before we begin, I want to remind you that during this call, we may make forward-looking statements within the meaning of federal securities laws. Such statements about future events may include statements about our financial outlook and performance, market size, our products and services, reimbursement coverage, future clinical performance and other similar statements. We caution you that such statements reflect our current best judgment, and actual results may differ materially from those expressed or implied in any forward-looking statements. Risk factors that may cause our results to differ are discussed in our filings with the SEC, including our previously filed registration statement on Form S-1, our previously filed quarterly report on Form 10-Q, our annual report on Form 10-K to be filed following this call and the current report on Form 8-K filed today. Any forward-looking statement made during this call is made as of today, March 4, 2026. If this call is replayed or reviewed after today, the information made during this call may not contain current or accurate information. BillionToOne disclaims any obligation to publicly update any forward-looking statements, whether because of new information, future events or otherwise, except as required by law. And with that, I will turn the call over to Oguzhan.

Good afternoon, everyone. Thank you for joining our fourth quarter and full year 2025 earnings call. It has been a great year for BillionToOne. I want to begin by expressing how truly proud I am of what our team accomplished in 2025. This was the year we proved what disciplined and relentless execution can truly achieve. This year, we did not just march our 20 miles. We did so by going public during a government shutdown that had frozen IPO markets and delivered, in my view, one of the most remarkable annual financial results in the history of molecular diagnostics. Let's look at our metrics. Forget the Rule of 40. Our full year 2025 performance exceeded the Rule of 100. For the full year 2025, we achieved 100% year-over-year growth with an adjusted EBITDA margin of 13%, a positive GAAP operating margin and positive cash flow. Delivering an organic rule of 100 is rare for any public company. In molecular diagnostics, I believe it may be unprecedented. This revenue growth is driven by rapid increase in both test volume and ASPs. Our test volumes grew by 51% compared to full year 2024. Our ASP grew by 35%. At the same time, we continued to decrease our costs and became more efficient. Our COGS per test decreased by more than 10%, even as we built our oncology business and processed vastly more oncology tests that have higher COGS. As a result, our gross margins improved by 15 percentage points. And as we incorporated AI and automation across all our functions, we achieved an even more remarkable increase in productivity, 36 percentage point improvement in our GAAP operating margin. This was due to an incredible combination of outperformance across all our teams. Our extremely strong sales team overachieved our test volume targets.…

Thank you, Oguzhan. As Oguzhan noted, total revenue in the fourth quarter of 2025 was $96.1 million compared to $45.1 million in the fourth quarter of 2024, representing an increase of 113%. Revenue growth for both our prenatal and oncology product lines was strong in the quarter. Prenatal revenues consisting of clinical testing revenues of $86.1 million and $800,000 in revenues from clinical trial support and other services increased 98% to $86.9 million in Q4. Oncology revenues increased 736% to $9.1 million in Q4 of 2025 versus Q4 last year. True-up revenue across both product lines was $8.4 million in the fourth quarter compared to $1.1 million in the fourth quarter of last year, reflecting higher cash collection trends related to tests delivered in prior periods. Revenues in the quarter were higher than the guidance we provided on December 9 of a range of $84 million to $90 million for Q4. About 2/3 of the higher Q4 revenues compared to this range was driven by higher test volumes than we expected and 1/3 was caused by higher true-up revenue compared to our estimate. Gross profit in the fourth quarter of 2025 was $68.6 million compared to $25.7 million in the fourth quarter of 2024, resulting in a gross margin of 71.4% in the fourth quarter of 2025 versus 57% in the fourth quarter of 2024. Importantly, ASPs and cost-per-test improved across all of our product lines year-over-year. Total operating expenses were $58.3 million in the fourth quarter of 2025 compared to $37.4 million in the comparable prior year quarter, representing an increase of 56%. Within operating expenses, R&D expense was $14.3 million in the fourth quarter of 2025 compared to $11 million in the comparable prior year quarter, while SG&A expense was $44 million in the fourth quarter of 2025…

Thank you, Ross. I would like to highlight that we have several additional growth drivers and catalysts in both prenatal and oncology that give us strong conviction that even our raised guidance is conservative. On the prenatal side, we see such strong continued momentum. We believe that the recently published clinical practice guideline will further position UNITY as the new standard in prenatal care and BillionToOne as the leading innovator in this field. The dual launch of our expanded Red Blood Cell Fetal Antigen NIPT and first-and-only Platelet Fetal Antigen NIPT at SMFM will further drive our growth. As awareness and practice guideline-driven adoption accelerate, we expect meaningful volume uplift in health systems where MFMs are the decision-makers. Such health system adoption is not reflected in our guidance. We also see continued ASP tailwinds from increased Medicaid coverage of our Carrier panel PLA code. 0449U has been added to 10 Medicaids in 2025, the largest of which has happened in Q4, with Florida starting to cover 0449U in Q1 2026. Each Medicaid addition can drive ASP increases and lead to further contracting with managed care organizations, MCOs, further driving our test volume in a flywheel. We also have several health systems that want to use UNITY as their prenatal screening of choice, with the only remaining blocker being the EMR integration. While the start of Epic Aura integrations is likely 6 months from now, and therefore, their contribution is not reflected in our guidance, adoption even in a single health system can be a significant upside to our projections. In oncology, the launch of Northstar Select PGx and Northstar Select CH broadened our oncology offering and deepened our value proposition for oncologists. As our test volumes grow, we are able to further drive our COGS per test down and enable…

[Operator Instructions] Our first question comes from the line of Andrew Brackmann of William Blair.

Thanks for all the remarks. Certainly a lot to dig into. Oguzhan, you mentioned the continued expansion of the prenatal portfolio as you continue to push that field forward. And certainly, I would think that this sort of increases the awareness of UNITY amongst certain providers. But if you could zoom out, can you maybe just sort of talk about where you think awareness is for all providers who order NIPT, both those who manage low-risk and high-risk pregnancies. And then how does that -- how do you sort of think about driving that higher in 2026 and beyond?

Thank you, Andrew. Very good question. And actually, this is one of the reasons why we believe we have such a long runway for our continued growth. When we -- I think this comes up in some of the surveys that analysts and others, including you have put together. But what we see in our own data that around -- depending on whether it is aided or unaided recall, at least 50% of providers do not know anything about UNITY. So that actually is a remarkable outcome that of the providers who know about UNITY, we actually have more than 50% market share or so. Around -- unaided awareness is around, I think, 30%, aided awareness is around 50%. So if you look at kind of those numbers and we look at essentially what percentage of them are actually using UNITY, we have about 50% market share if a provider knows about our tests. So from that perspective, we believe that as we continue to increase our sales team size, as we continue to cover the entirety of the United States fully, and as we continue to publish and have these clinical guideline changes and other additional products with UNITY, we believe that this awareness is going to increase, and that is going to be a really big driver of our long-term growth.

And then maybe if I could just follow up the commentary around health systems where MFMs are an important decision-maker there. Can you maybe just sort of talk about the conversations that you're having with those groups, in particular, around sort of driving uptake across these larger groups?

Certainly. MFMs are an important stakeholder, right? They are usually the ones that are taking care of the high-risk pregnancies. And when any NIPT determines a high-risk result, usually, these patients are referred to MFMs. So from that perspective, MFMs have tremendous influence over the tests that the OBs who are referring their high-risk patients to them have. So in general, this is important in health systems where those OBs and MFMs work very closely, but it is even actually important outside of the health system context where an MFM can go to the OBs who are referring their patients to them and say that, I would rather -- if they are a big advocate of UNITY, they can say that, I would rather have you use UNITY for your frontline screening in that way, when I get these high-risk patients, I have all the information that I need to be able to counsel them, to be able to manage them, to be able to treat them.

Our next question comes from the line of Dan Arias of Stifel.

Oguzhan, can you maybe talk about the new provider increased number that you mentioned for Northstar? How should we think about that as a metric? What would you consider good versus not good this year when it comes to bringing new docs on board? Just sort of would be helpful to understand how you're expanding usage in the market.

Thank you, Dan. The number that I referred to was combined across prenatal and oncology. So when we looked at the number of ordering providers, active ordering providers that we have in every quarter, what we have seen in Q4 is that number of active ordering providers actually significantly increased. That was the best quarter in terms of active ordering providers that we have been able to add. What that usually means is very strong growth for Q1. As we previously mentioned, because Q4 is fewer number of accessioning days, the true impact on the test volume growth is usually not reflected in the Q4 numbers. But if you look at the number of active ordering providers, and we actually have a high bar for calling a provider an active ordering provider. If they order just 1 or 2 tests, that doesn't count. So from that perspective, what that comment is really referring to is, compared to all the previous quarters, Q4 was actually the strongest quarters in terms of having new active providers that are not just dabbling in or using 1 or 2 tests, but that are using our products regularly within the quarter, which means usually a very strong signal for where the Q1 test numbers are going to end up with.

Okay. Okay. And then Ross, Oguzhan made a comment on gross margins. Is it right to think that the assumption is flat gross margins for the year? And then are you comfortable with that across the guidance range and across the range of mixes that you might see? I mean I know you can control that mix, but I just want to kind of make sure that that's a fully underwritable number sort of regardless of scenario.

Yes. Good question, Dan. I think we're not giving a whole lot of color around gross margins or some of the expense lines other than to say we want to operate the business with positive operating income on a GAAP basis going forward. But I would expect the gross margins to stay up in that high 60-ish range. Maybe we could continue somewhere in this 71%, low 70% range. But I think I would not get aggressive at all in terms of expectations for expansion in gross margin.

Our next question comes from the line of Mark Massaro of BTIG.

Congrats on a strong year and certainly a lot to dig into as well. I wanted to ask about the United contract going in-network. I presume this is for UNITY, although UNITY is not your only product in the market. So can you just speak to which products the United contract covers? And then historically, in diagnostics, sometimes people negotiate in-network with large health plans, and they have to take maybe a price discount. Can you just speak to how we should be thinking about that dynamic, whether or not we should expect slightly lower ASPs as a result of this going in-network?

Thank you, Mark. I think you should expect higher ASPs going forward. We have signed over the course of last 4 years, probably close to 200 contracts and not a single one decreased our ASPs. So from that perspective, when you get in-network with a payer more broadly, what happens is that you do agree to a percentage of Medicare as part of that contract. But that also means that you get reliable reimbursement for that percentage rather than the amount actually going into the coinsurance and deductible of patients. So given the patient collections are not -- are never really 100% despite best efforts, what typically happens is that you might agree to a lower percentage, let's say, 80%, 70% of Medicare, but that ends up being significantly higher than what you would otherwise get on a blended ASP basis. I can't go into the specifics of a contract due to confidentiality reasons. But what I would say is that we, again, also typically see that for every contract that we sign, it is actually for both -- all the products that you have. It is for prenatal and oncology products. That doesn't mean that a test -- every test is going to get paid, right? It is -- you need to have the coding, you need to have the coverage as well. So you need to have the contract and contract will cover what codes that you have, but that should also need to be -- there needs to be the coverage for a test to be paid. So from that perspective, [ there comes a benefit ]. And again, this is public information that can be found with UnitedHealthcare, including with many of the commercial contracts that we have.

Okay. Great. And then maybe as a follow-up, can you just speak to what you might be seeing in the field? I know Natera launched Fetal Focus, if you're seeing any impact there. And then if I can ask a cleanup, pharmacogenomics and Northstar Select CH, these are add-on products. Is this a potential source of additional ASP? In other words, will you be charging for these tests?

So taking on the oncology question first, the Northstar Select CH and PGx are add-ons to our existing tests. We do not typically expect to see significant ASP lifts coming from such add-ons, especially in the short term. In the long term, as guidelines evolve and the current guidelines with respect to ESMO, for instance, still -- they are already supportive of buffy coat sequencing with respect to CH, there can be ASP lifts as these become covered benefits. With respect to the competition, I think as you can see from the fact that we have added a record number of ordering providers in Q4, our test volume growth numbers in Q4 and the way that our prenatal revenues are increasing, I think it is relatively straightforward to conclude that we are actually not seeing any impact from the competition so far.

Our next question comes from the line of Subbu Nambi of Guggenheim.

Oguzhan, this is your second quarter reporting as a public company. As you reflect on these first 2 quarters, what has gone according to plan so far? And what has exceeded your expectations? And what could have gone better and is an area of focus for improvement in 2026?

Thank you, Subbu. I think we have been operating similar to this cadence for the last 3 years. And this is something that our pre-IPO investors would easily attest to. We have reported quarterly results and beat and raise our guidance past 3 years. In fact, our Board members will tell you that we never really missed the guidance in the time that they have been an investor. So from that perspective, everything has been going according to the plan. That doesn't mean that everything that you work on essentially ends up being -- ends up giving you better results. It is just that we work on a number of drivers, and many of those drivers are not embedded into the guidance. So if some of them turn out to be true, that still ends up having an upside to what we originally expected our results to be. In terms of what maybe did not go according to the plan, because perhaps of the timing of the IPO and the earnings calls, it has been a lot of conferences and investor meetings and earnings calls. We certainly prefer to focus on running the company and building the business to participating in the conference, no offense intended.

Oguzhan, as a complete separate follow-up, you discussed a bit about some of the upside opportunities for prenatal volumes versus the guidance. But could you discuss what the guidance assumes in terms of prenatal volume growth today and prenatal market share gains? And given the growth you have seen in prenatal volumes, you haven't been impacted by seasonality. But as you think about 2026, do you expect to see more seasonality just because of the volume, the sheer number of volumes?

We typically see Q4 always being a slower quarter for us. As we previously mentioned, we -- there are a lot of physicians who do not want to switch their test during Q4. They kind of leave the decision to the beginning of the year. There are also fewer accessioning days in Q4. So the combination of those 2 factors tend to make our Q4s slower. So it was actually a sign of particular strength in our business that we did not see a slowdown in Q4. And that, I think, really bodes extremely well for what we expect Q1 to be and the rest of the year to be. In terms of what our guidance incorporates, it really incorporates essentially our existing number of sales team members and how we expect them to grow on a quarter-over-quarter basis, essentially what they need to do to maintain and grow each of their territories. It does not include a lot of the upside that can come in from these large health system opportunities, which can be driven by either these guideline changes and the new product additions that we have had as well as the Epic Aura integrations that we mentioned. So any health system or any health system-related adoptions are not really incorporated into our guidance.

Our next question comes from the line of David Westenberg of Piper Sandler.

Congrats on the first couple of great quarters out of the IPO gate. So maybe I missed this because I can't believe no one asked this. But in the last 2 months, you raised guidance by $15 million at the endpoint. Can you give us maybe some of the details on what kind of went right over the last 2 months, what you see difference? I mean I know you have United, maybe that's a contributor. Is that purely the contributor? Anything else to think about there?

We did not incorporate any potential upside that would come from United to our revenues. United contract is effective April 1. Ross had one sentence, I think, in his prepared remarks where he mentioned that compared to the guidance that we had in December, the 2/3 of the increase came from the strength in the test volumes and 1/3 came from higher-than-expected true-up revenue. So it's essentially, we came into December with the idea that Q4s tend to be a little bit seasonally slower for us. We had October and November numbers and December ended up being extremely strong with respect to the test volumes, which ended up driving 2/3 of the beat and the 1/3 came from the fact that we had higher-than-expected true-up revenue in the quarter. For the new year guidance, we actually did not incorporate any of the developments and the upsides and drivers that we talked about. We essentially took the expectation of on a per test per sales rep growth in different territories. And then we just incorporated what our quantitative numbers are in Q4, and this is the quantitative result of that model. So we believe that, that is why it is very conservative.

Perfect. And then maybe I was just going to ask in terms of getting paid on response. I mean how are the conversations going with CMS? And there's not many response assays out there. I mean there's Guardant Response essentially. How are you anticipating this coverage policy kind of looking like? I know there's different histology types in monitoring, maybe it kind of looks more like MRD. What are kind of the pushes and pulls that CMS might look at? And I'll take it offline from there.

So MolDX under its existing policy already covers the concept of treatment monitoring. This policy was written primarily for MRD, but there is a section that actually covers how they think about treatment monitoring, and that clear line of sight to what we need to provide. We have started some of those conversations, but of course, it always takes a few back-and-forth submissions before you get to a coverage decision. So that is why we are still planning for the end of the year for the coverage decision from MolDX for Medicare lives.

Our next question comes from the line of Casey Woodring of JPMorgan.

Just curious on what you guys are seeing in the therapy selection and response monitoring competitive markets and if you're bumping into other competitors there, one of the -- your larger competitors is talking more about response monitoring. And then would be curious to hear what's embedded in the guide for oncology volume growth and how that's split across between existing providers versus share gains? And would also be curious to hear what the average test order per month is for existing customers of Northstar Select.

Can you repeat the first question? I think that was 3 questions. I want to make sure that I cover everything.

Yes. No, I'll get. Just on the therapy selection competitive market, you're bumping into competitors there and on therapy response monitoring as well, just given one of your larger competitors is talking more about that test.

Certainly. And I think it is a clear recognition of that there is a tremendous need for response monitoring. And we are seeing competition, both with therapy selection and response monitoring in the market. With respect to therapy selection, the fact that we are able to most sensitively identify 50-plus percent more actionable variants is really a game changer. So for us, it is really about getting in front of the oncologists that tends to be the bottleneck. Once we are in front of an oncologist, we have peer-reviewed publications that show a head-to-head prospective study. But even when a particular oncologist may not think that, that particular study would apply to their patient population, 50% more actionable variants is such a large number that they need to just see it for themselves for 5 or 10 patients within their context. So from that perspective, we are able to tell them, why don't we do a research trial with you where you send us 5 or 10 of your patients for research purposes where you are running them with standard of care with one of the larger competitors that we have. And we are winning those head-to-head studies and you really need one patient. If one patient's treatment journey changes because you identified an actionable variant that changed that patient's treatment journey or that your competitor didn't identify or they identified the CHIP mutation that we were able to classify as CHIP and say that this patient is not going to respond to this therapy. In both of those cases, just one patient completely changes that physician's view of your test. It only takes one patient that physician doesn't just become a user of your test, but they become an advocate for your test. This is actually where we are seeing a flywheel effect. When we initially put a sales rep in a particular region, because there is so much competition, it can take 3, 6, 9 months for them to get in front of oncologists sometimes. It is not just the diagnostics competition. It is all the pharmaceutical sales reps in oncology that are booking lunches that are taking oncologists' time. But once you have 1 or 2 or 3 physicians who are not just users, but are advocates. They are passionate about what this test does for their patients. They refer -- they advocate for your test to other physicians, which allows you to get in front of them much faster. So one thing that we are seeing is that in territories, as we kind of increase our test volume, it is actually becoming easier and easier because we are able to remove that bottleneck of being in front of oncologists, which is really the only bottleneck against our ability to win against the competition.

Got it. That's helpful. And then, yes, maybe just a quick follow-up. What's embedded in the guide for oncology volume growth? And how does that split across growth between existing providers and share gains? And would also be curious to just hear if you have an average test order per month for existing customers with Northstar Select. That's a question we'll get every now then.

I do not have a number for the average test out at Select per physician. In terms of the kind of share gains or how we are thinking about the guidance, it is exactly the same way that we think about prenatal. We know that on average, each of our sales reps is able to grow x number of tests per quarter. And that allows -- and we have seen that over the course of last 2 years with more than 40, 45 reps. So we essentially incorporate that growth into our test volume increase for oncology for 2026.

[Operator Instructions] Our next question comes from the line of Brandon Couillard of Wells Fargo.

Ross, in terms of the guide, should we be thinking about the ASP growing from the baseline of $560 in the fourth quarter? And are you assuming any true-up revenue tailwind going forward in the revenue guide?

Good question, Brandon. The revenue guide does not include any true-up revenue, so that's exclusive of true-up revenue. And I think as you think about our overall ASP, do remember that the way we compute it historically, we do include the true-up revenue. So you may want to make some adjustments or make assumptions around that.

Okay. Then, Oguzhan, can you just talk about the sales force expansion plans for '26? I mean you've been growing at a pretty ratable pace, both in oncology, call it, 8, 9, 10 reps a quarter and prenatal. Do you expect to accelerate that at all or make any adjustments in response to competition or some of the new products that you're obviously excited about?

Thank you, Brandon. As we shared in the earnings deck, we expect to maintain our growth for prenatal and oncology. Prenatal is slated to grow from 150 roughly to 185 reps by the end of the year, and oncology is expected to grow around from 45 reps to 65 reps by the end of the year. This level of growth is actually chosen not because we cannot grow faster, we certainly can. But this is the kind of maximum level of growth that we feel comfortable about in terms of maintaining the quality of our test, right? You can have the most amazing oncology test. But if your test volume is increasing more than 100% year-over-year, it becomes actually very difficult to maintain the same turnaround time, the same quality of service with those tests. So we essentially are doing this very systematic growth also because this allows us to have a level of growth that we believe is going to allow us to maintain the same level of service, right? And even if you have a great test, if your turnaround time goes from 5 days to 15 days, you are going to lose customers, especially for these very time-sensitive important tests. So from that perspective, our sales team growth numbers is set up in such a way that it will enable us to have excellent end-to-end service, all the way from client services to lab operations to everything that we do. And in that way, it also is done in such a way that prenatal growth balances some of the oncology growth with respect to the GAAP profitability.

Our next question comes from the line of Tycho Peterson of Jefferies.

This is Noah on for Tycho. I wanted to start by asking about the health systems opportunity, particularly if you could provide any context on how you're sizing it and then what the time line looks like for this to possibly show up the numbers?

Thank you. The way that we think about the health system opportunity that each health system can be really anywhere between 10,000 to 30,000 tests per year. And so these are really large health systems that take time, right, that take multiple stakeholders to be on the same page. And we do have a number of health systems where we have clinical buy-in, but we still need to get integrated with EMR before they can roll out our test as their frontline screening of choice. Given that this is not completely under our control, right? This is -- we first need to integrate with Epic and then we need to integrate with each health system, and that can take time. We haven't incorporated any of these uplifts into our test numbers for 2026. That said, given what we are seeing here, I think, especially in the second half of the year, there can be opportunities for 1, 2, 3 of these health systems to start coming in. Of course, for 2026, you are not going to see that full impact of 10,000 to 30,000 tests if they come in, in the middle of the year. But as we look at 2027, those adoptions, those wins will set us up for another extremely strong year of growth.

That's helpful color. And then for my follow-up, I just wanted to dive into the guidance a bit more. So for 1Q, should we expect any potential disruptions from weather impact? And then on the OpEx side, is there any phasing to consider throughout the year in terms of spending on MRD trials or incremental hires ahead of the launch?

In terms of weather impact, you should not expect anything because our Q1 -- with Q4 setting up Q1 very nicely, we expect to have a strong 2026, including Q1. In terms of any impact on OpEx, we are continuing to invest at a pace that would continue to make us GAAP profitable. So we do not anticipate any kind of either front-loading or end-loading of OpEx. It is a very balanced plan, not just actually for this year, but across the course of next 3 years.

Thank you. I would now like to turn the conference back to Oguzhan Atay for closing remarks. Sir?

Thank you, operator, and thank you all for joining today's conference call. We look forward to speaking with you on our next conference call in a few months. We had a really strong 2025, but we are even more looking forward to what we will achieve in 2026. Have a good day.

This concludes today's conference call. Thank you for participating. You may now disconnect.