I haven’t added any Bioventix (LSE:BVXP) shares to my Stocks and Shares ISA, but could 2026 be an excellent time to rethink that?
The niche biotech group manufactures monoclonal antibodies critical for clinical diagnostics, combining a direct sales business model with downstream royalties. And while cash flows can be occasionally lumpy, dividends have nonetheless been on a steady upward trajectory over the last decade.
So with the yield now sitting at a staggering 8.3%, is this a screaming buy for my ISA?
Inspecting the yield
In its 2025 fiscal year (ending in June), Bioventix made a slight downward adjustment to the dividends paid per share, from 155p to 150p, in line with its cash flow. But despite this, the yield’s shot through the roof, primary as a result of the stock price taking a nasty 43% tumble over the last 12 months.
What happened? There’s a variety of factors at play here. But one of the biggest disappointments in the group’s 2025 results so far was the royalty performance of its troponin antibodies used for cardiac risk assessment.
With troponin now being used beyond investigating chest pains in hospital A&E departments, investors were expecting an uptick in both sales and royalty income. But sadly, that didn’t materialise. And while management’s confident in growth emerging in 2026, investor sentiment’s nonetheless suffered.
The situation in China hasn’t helped matters either. With the Chinese government implementing its ‘China First’ policies, local antibody manufacturers are getting increasingly promoted, making it much harder for Bioventix to compete. And with a large chunk of revenue coming from this region, it presents a significant headwind.
As a consequence, Bioventix’s earnings per share slipped by 6.3% to 143.29p. And since that’s now lower than the 150p paid out in dividends, investors are understandably getting nervous.
A hidden opportunity?
Paying out more to shareholders than the company’s bringing in is obviously unsustainable in the long run. But if revenues and earnings can get back on track, Bioventix’s high yield could indeed be a stellar income opportunity. And right now, there are some catalysts for cautious optimism.
The emerging Alzheimer’s diagnostics market is expanding rapidly and relies on Tau antibodies – something that Bioventix is already capitalising on. In 2025, £605k in revenue was generated from these products, up from £155k the year before. And if management’s outlook on troponin proves accurate, 2026 could indeed see a return to sales and earnings growth momentum.
Of course, forecasts are never set in stone. The use of Tau antibodies is still in a relatively early innings. And the shifting landscape in China could represent a critical structural headwind rather than a temporary cyclical one.
Continued stagnation of troponin antibodies, along with rising competition for its other high-growth potential products, could prevent Bioventix from unleashing its full potential. And, in turn, that could result in dividends falling even further.
The bottom line
Bioventix presents a unique opportunity for my Stocks and Shares ISA, offering both growth and dividend potential. But with a lot of short-term uncertainty, I’m keeping this small-cap stock on my watchlist for now. But if Tau antibody sales continue to accelerate, investors may want to take a closer look.
