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BLLN in the 13F filings

BillionToOne Inc · CUSIP 090168105

New listing in Q4 2025· first held by a tracked manager this quarter, so its new positions are allocations rather than a turn towards it

Sector · Health care services and research
Quarter
Q3 2026 · early filersQ2 2026Q1 2026Q4 2025
Quarter end
31 Dec 2025
the date the book describes
Filed
27 Oct 2026
latest of these filings; the earliest 22 Jan 2026
Managers listing it
17
at least, of 95 tracked, among listed positions
Comparable managers
92
filed both Q3 2025 and Q4 2025; 0 listed it in both
Shares listed
3,279,763
combined, among listed positions
Reported value
$268m
combined, at the quarter end

1 line marked †. Value as filed implies a price far from other filers'. Each counts in holders and value as filed, and is left out of the net change in shares.

Among the 92 comparable managers: 17 buyers (opened or added shares) and 0 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was +3,275,206.

Managers listing BLLN in Q4 2025

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q3 2025, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

17 of 17 holders

ActionFiling
Baillie Gifford & Co1,268,163$104m0.09%Newnew23 Jan 2026 (the filing on sec.gov)
Neuberger Berman Group LLC700,867$57munder 0.1%Newnew27 Oct 2026 (the filing on sec.gov)
T. Rowe Price Associates Inc485,283$40munder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)
AllianceBernstein LP208,594$17munder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)
Invesco Ltd189,819$16munder 0.1%Newnew19 Feb 2026 (the filing on sec.gov)
MFS Investment Management163,400$13munder 0.1%Newnew22 Jan 2026 (the filing on sec.gov)
Citadel Advisors LLC148,868$12munder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)
Verition Fund Management LLC33,311$2.7munder 0.1%Newnew13 Feb 2026 (the filing on sec.gov)
Marshall Wace LLP20,902$1.7munder 0.1%Newnew13 Feb 2026 (the filing on sec.gov)
Woodline Partners LP17,000$1.4munder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)
Soros Fund Management LLC14,500$1.2munder 0.1%Newnew13 Feb 2026 (the filing on sec.gov)
Squarepoint Ops LLC7,891$646kunder 0.1%Newnew13 Feb 2026 (the filing on sec.gov)
Walleye Capital LLC5,960$488kunder 0.1%Newnew13 Feb 2026 (the filing on sec.gov)
Millennium Management LLC5,706$467kunder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)
Brevan Howard Capital Management LP† Value as filed implies a price far from other filers'.4,557$394kunder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)
Schonfeld Strategic Advisors LLC4,242$347kunder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)
Fidelity (FMR LLC)700$57kunder 0.1%Newnew17 Feb 2026 (the filing on sec.gov)

Largest increases and reductions, by shares

There is no earlier quarter on file to compare with.

Increases

Reductions

No reduction among listed positions.

New positions and exits

At least these many: a manager is shown exiting only where its own filing shows the position gone.

New (17)

Exited (0)

No exit shown by a manager’s own filing.

Ownership over time

Every quarter on file. A quarter-end value moves with the price as well as with the shares held; buyers and sellers count comparable managers, by shares.
3 in Q4 2025 to 5 in Q2 2026

Tracked managers listing it, at least.

0246Q4 2025Q1 2026Q2 2026
the quarter shown share split complete books; unmarked quarters rest on listed positionsClick a quarter to open it.
BLLN by quarter
QuarterHoldersReported valueBuyersSellers
Q4 20253$162m170
Q1 20262$101m1110
Q2 20265$219m187

Compare with…

Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.

BLLN and UNH →BLLN and ELV →BLLN and CI →Choose a stock to compare with BLLN →

How much of the picture this is

A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.

Which funds own BLLN, latest filings →Back to the 13F Explorer →