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For those who have invested Nvidia stock back in the day and on and on, returns have been amazing. It delivered a 10-year return of 75.3% in high-quality terms.
One FTSE 250 investment trust that has gained Baillie Gifford US Growth Trust. Between March 2018 and late 2025, its investment in Nvidia increased 3.155%!
Given Baillie Gifford’s track record of finding high growth stocks like Nvidia and Teslait’s worth looking at what new stocks it’s been buying. And a new name in the US Growth Trust portfolio caught my eye.
Let’s take a closer look at this under-the-radar company – which recently went public and is already one of the trust’s largest holdings – to see what the fuss is about.
Stock
BillionToOne (NASDAQ:BLLN) is a medical diagnostics company. Its Quantitative Counting Templates platform is the only patented technology that can count DNA molecules with single precision on a large scale.
Having dug into the company, I see a few interesting things here. First, BillionToOne operates in two high-growth diagnostic markets: prenatal diagnostic testing and cancer screening. The company estimates its total addressable market at around $100bn in the US alone.
It’s encouraging to see the company taking advantage of this opportunity, with Q3 revenue up 117% year-on-year to $83.5m. It delivered 165,000 tests, a 52% increase.
Management is guiding 2026 revenue of $415m to $430m, which would represent growth of 40% to 45%. Most of its revenue comes from prenatal screening, which tests for conditions like cystic fibrosis and sickle cell using only the mother’s blood, but its cancer screening is growing rapidly.
Another advantage is that the company does not burn money. It expects to report a healthy operating profit for the full year, with strong margins of around 70%. So this has the potential to be a very lucrative business.
Finally, the company’s market value today is just $3.9bn. These days, that’s not a big deal. A company can be very big if it seizes the trading opportunity ahead.
After all, Nvidia’s market cap was roughly this size back in 2013.
Our long-term goal is to build a category-defining manufacturing company and become a member of the S&P 500..
BillionToOne
My first step
In retrospect, I see a few things here that indicate BillionToOne could be a great growth stock. Unlike many early growth firms, it is already targeting strong margins and sustainable profitability through 2026.
On top of this, there is strong institutional investor support and great potential for international expansion. It also works in early cancer screening, which could be the most exciting market of all.
However, it’s too early to call it a slam-dunk winner, let alone give it Nvidia-esque power. There is a lot of competition in this space from A life guard again Nateraand I am concerned that a new diagnostic breakthrough may threaten the company’s technology at some point.
Meanwhile, the number of sales is around 10, so there is a lot of growth baked into the current ratio.
For now, I think it’s the one to keep an eye on. BillionToOne will report Q4 earnings in early March.
