Institutional HoldersBeta

Who holds a company, from every 13F filed for the quarter, one row per filer exactly as filed, against the latest share count the company reported.

SERA PROGNOSTICS, INC.

CIK 0001534969SERA· quarter ending 2026-06-30

Shares outstanding

39,449,466

as of 2026-08-07 · 10-Q cover page, filed 2026-08-12

Held by 13F filers

17,056,699

44.3% of Common Class A

Holders

-9 vs 2026-03-31 · 1 new, 10 exited

Value

$31.0M

shares -14.5% vs prior quarter

Share classes (cover page of the 10-Q filed 2026-08-12, as of 2026-08-07)

Class	Listed	Shares outstanding	Held by 13F filers	% of class	Holders	CUSIP
Common Class A	SERA · NASDAQ	38,481,707	17,056,699	44.3%	47	81749D107
Common Class B	not listed	967,759	—	—

Each class is compared with its own share count; classes are not added together. A class that is not exchange-listed cannot be held by 13F filers.

Securities (CUSIPs held in 13F this quarter)

tick to combine

Count	CUSIP	Class (as filers write it)	Holders	Shares held	Class shares	% of class	Value	Options	Mapped via
	81749D107	Stock	47	17,056,699	38,481,707	44.3%	$31.0M	—	13DG	holders →

Totals combine the ticked CUSIPs and update as you tick: common-stock classes by default; preferreds, notes, warrants and depositary shares are listed but not counted. "holders →" shows a single CUSIP on its own. Bonds are held as a principal amount, not shares. Options positions are never counted as holdings.

Top holders (47 of 47 · 81749D107)

change vs 2026-03-31

#	Filer	Shares	% of class	Value	Change
1	BAKER BROS. ADVISORS LP	5,498,170	14.29%	$10.0M	—
2	Whetstone Capital Advisors, LLC	3,306,889	8.59%	$6.0M	—
3	Aberdeen Group plc	2,753,525	7.16%	$5.0M	+202,750 (+7.9%)
4	Vivo Capital, LLC	1,650,440	4.29%	$3.0M	—
5	VANGUARD CAPITAL MANAGEMENT LLC	1,297,792	3.37%	$2.4M	+93,677 (+7.8%)
6	CAPTRUST FINANCIAL ADVISORS	535,755	1.39%	$975K	-1,006 (-0.2%)
7	GEODE CAPITAL MANAGEMENT, LLC	348,967	0.91%	$635K	-14,650 (-4.0%)
8	BlackRock, Inc.	221,369	0.58%	$403K	+25,264 (+12.9%)
9	AWM Investment Company, Inc.	207,382	0.54%	$377K	—
10	VANGUARD FIDUCIARY TRUST CO	170,908	0.44%	$311K	+1,247 (+0.7%)
11	STATE STREET CORP	124,792	0.32%	$227K	—
12	MILLENNIUM MANAGEMENT LLC	73,986	0.19%	$135K	-17,518 (-19.1%)
13	Perigon Wealth Management, LLC	72,685	0.19%	$132K	—
14	NORTHERN TRUST CORP	68,595	0.18%	$125K	-27,940 (-28.9%)
15	Bank of New York Mellon Corp	60,927	0.16%	$111K	—
16	BRIDGEWAY CAPITAL MANAGEMENT, LLC	55,705	0.14%	$101K	+10,000 (+21.9%)
17	Requisite Capital Management, LLC	55,648	0.14%	$101K	—
18	MORGAN STANLEY	50,972	0.13%	$93K	-54,045 (-51.5%)
19	Qube Research & Technologies Ltd	50,871	0.13%	$93K	+30,954 (+155.4%)
20	Ballentine Partners, LLC	49,664	0.13%	$90K	—
21	Twelve Points Wealth Management LLC	43,388	0.11%	$79K	—
22	HighTower Advisors, LLC	42,234	0.11%	$77K	—
23	CITADEL ADVISORS LLC	41,411	0.11%	$75K	-207,498 (-83.4%)
24	Catalyst Funds Management Pty Ltd	38,890	0.10%	$71K	+15,326 (+65.0%)
25	GOLDMAN SACHS GROUP INC	32,541	0.08%	$59K	+14,069 (+76.2%)
26	DIMENSIONAL FUND ADVISORS LP	29,499	0.08%	$54K	+9,964 (+51.0%)
27	Birch Hill Investment Advisors LLC	27,293	0.07%	$50K	—
28	Cetera Investment Advisers	25,000	0.06%	$46K	—
29	XTX Topco Ltd	16,808	0.04%	$31K	+317 (+1.9%)
30	TWO SIGMA INVESTMENTS, LP	16,221	0.04%	$30K	-5,743 (-26.1%)
31	Riverview Capital Advisers, LLC	12,669	0.03%	$23K	—
32	Wagner Wealth Management, LLC	12,400	0.03%	$23K	—
33	Focus Partners Wealth	12,156	0.03%	$22K	—
34	UBS Group AG	11,309	0.03%	$21K	-3,560 (-23.9%)
35	Vanguard Global Advisers, LLC	11,169	0.03%	$20K	—
36	Geneos Wealth Management Inc.	10,800	0.03%	$20K	—
37	WEALTH ENHANCEMENT ADVISORY SERVICES, LLC	10,504	0.03%	$21K	-54 (-0.5%)
38	BARCLAYS PLC	3,179	0.01%	$6K	-28,788 (-90.1%)
39	FMR LLC	2,539	0.01%	$5K	-4,034 (-61.4%)
40	Global Retirement Partners, LLC	1,000	0.00%	$2K	NEW
41	JPMORGAN CHASE & CO	222	0.00%	$402	—
42	BNP PARIBAS FINANCIAL MARKETS	186	0.00%	$339	-50 (-21.2%)
43	NISA INVESTMENT ADVISORS, LLC	129	0.00%	$235	—
44	Silicon Valley Capital Partners	57	0.00%	$104	—
45	ROYAL BANK OF CANADA	45	0.00%	$0	+2 (+4.7%)
46	Caitong International Asset Management Co., Ltd	4	0.00%	$7	—
47	SBI Securities Co., Ltd.	4	0.00%	$7	-3 (-42.9%)

Exited since 2026-03-31 (10 filers; largest 10 shown)

PSP Research LLC	−2,396,685
SANDERS MORRIS HARRIS LLC	−314,950
GSA CAPITAL PARTNERS LLP	−104,973
JANE STREET GROUP, LLC	−53,908
Squarepoint Ops LLC	−31,428
Arkadios Wealth Advisors	−12,400
CHARLES SCHWAB INVESTMENT MANAGEMENT INC	−12,085
CWM, LLC	−1,003
Optiver Holding B.V.	−412
Advisory Services Network, LLC	−19

Large holders from 13D/13G (latest per reporting person, last 2 years)

Filed when a holder crosses 5% or changes materially, so often more current than the quarter-end 13F. Percentages are the filer's own, against the share count they used.

Reporting person	Form	Filed	Event	Shares	% of class
abrdn Inc.	SCHEDULE 13G/A	2026-07-15	2026-06-30	2,753,525	7.21%
Aberdeen Group plc	SCHEDULE 13G/A	2026-07-15	2026-06-30	2,753,525	7.21%
Whetstone Capital Advisors, LLC	SCHEDULE 13G/A	2026-05-01	2026-03-31	3,306,889	8.6%
David Atterbury	SCHEDULE 13G/A	2026-05-01	2026-03-31	3,306,889	8.6%
Peter Kolchinsky	SCHEDULE 13G/A	2025-08-14	2025-06-30	0	0%
Rajeev Shah	SCHEDULE 13G/A	2025-08-14	2025-06-30	0	0%
RA Capital Management, L.P.	SCHEDULE 13G/A	2025-08-14	2025-06-30	0	0%
RA Capital Healthcare Fund, L.P.	SCHEDULE 13G/A	2025-08-14	2025-06-30	0	0%
Vivo Capital IX, LLC	SCHEDULE 13G/A	2025-05-15	2025-03-31	1,650,440	4.5%
Baker Bros. Advisors (GP) LLC	SCHEDULE 13D	2025-02-14	2025-02-12	5,498,170	16.1%
Marcin Czernik	SCHEDULE 13D/A	2025-02-14	2025-02-11	2,605,351	7.6%
Julian C. Baker	SCHEDULE 13D	2025-02-14	2025-02-12	5,498,170	16.1%
Felix J. Baker	SCHEDULE 13D	2025-02-14	2025-02-12	5,498,170	16.1%
Chione Ltd.	SCHEDULE 13D/A	2025-02-14	2025-02-11	2,605,351	7.6%
Baker Bros. Advisors LP	SCHEDULE 13D	2025-02-14	2025-02-12	5,498,170	16.1%
Andreas Hadjimichael	SCHEDULE 13D/A	2025-02-14	2025-02-11	2,605,351	7.6%
Anastasis Nikolaou	SCHEDULE 13D/A	2025-02-14	2025-02-11	2,605,351	7.6%
Wiaczeslaw Smolokowski	SCHEDULE 13D/A	2025-02-14	2025-02-11	2,605,351	7.6%

Source: SEC Form 13F-HR information tables for the quarter ending 2026-06-30 (filed within 45 days of quarter end; amendments applied; values normalised to dollars), the share count from the company's latest 10-K/10-Q XBRL cover page, and Schedule 13D/13G filings. Each row is a legal 13F filer as filed — related entities (e.g. Vanguard's advisers) are not merged. Retail brokerage accounts are not reported on 13F, so the remainder is mostly retail and insiders.