Sera Prognostics, Inc. (SERA) Ownership
SERA ownership summary
as of October 18, 2026- Institutions
- 51.0% of shares outstanding
- Insiders
- 12.11% of shares outstanding
- Shares outstanding
- 38.5M
- Float
- 27.7M shares available to trade
- Short interest
- 0.73% 230K shares short
- Days to cover
- 10.40 short interest up 7.4% vs prior month
- Institutions 51.02%
- Insiders 12.11%
- Other investors 36.87%
SERA top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Baker Bros Advisors LP | 13.94% | 5.5M | $11.3M | — | June 30, 2026 |
| 2 | Whetstone Capital Advisors, LLC | 8.38% | 3.3M | $6.8M | — | June 30, 2026 |
| 3 | Aberdeen Group PLC | 6.98% | 2.8M | $5.7M | +202,750 (+7.9%) | June 30, 2026 |
| 4 | Vivo Capital, LLC | 4.18% | 1.7M | $3.4M | — | June 30, 2026 |
| 5 | Vanguard Capital Management, LLC | 3.29% | 1.3M | $2.7M | +93,677 (+7.8%) | June 30, 2026 |
| 6 | CapTrust Financial Advisors | 1.36% | 536K | $1.1M | −1,006 (−0.2%) | June 30, 2026 |
| 7 | Geode Capital Management, LLC | 0.88% | 349K | $718,872 | −14,650 (−4.0%) | June 30, 2026 |
| 8 | BlackRock Inc | 0.56% | 221K | $456,020 | +25,264 (+12.9%) | June 30, 2026 |
| 9 | Awm Investment Company Inc | 0.53% | 207K | $427,207 | — | June 30, 2026 |
| 10 | Vanguard Fiduciary Trust Co | 0.43% | 171K | $352,070 | +1,247 (+0.7%) | June 30, 2026 |
| 11 | State Street Corp | 0.32% | 125K | $257,072 | — | June 30, 2026 |
| 12 | Millennium Management LLC | 0.19% | 74K | $152,411 | −17,518 (−19.1%) | June 30, 2026 |
| 13 | Perigon Wealth Management, LLC | 0.18% | 73K | $149,731 | — | June 30, 2026 |
| 14 | Northern Trust Corp | 0.17% | 69K | $141,306 | −27,940 (−28.9%) | June 30, 2026 |
| 15 | Bank of New York Mellon Corp | 0.15% | 61K | $125,510 | — | June 30, 2026 |
| 16 | Bridgeway Capital Management, LLC | 0.14% | 56K | $114,752 | +10,000 (+21.9%) | June 30, 2026 |
| 17 | Requisite Capital Management, LLC | 0.14% | 56K | $114,635 | — | June 30, 2026 |
| 18 | Morgan Stanley - Brokerage Accounts | 0.13% | 51K | $105,002 | −54,045 (−51.5%) | June 30, 2026 |
| 19 | Qube Research & Technologies | 0.13% | 51K | $104,794 | +30,954 (+155.4%) | June 30, 2026 |
| 20 | Ballentine Finn & Company Inc | 0.13% | 50K | $102,308 | — | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 6 holders added 364K shares and 5 cut 115K.
SERA top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | abrdn Healthcare Opportunities | 3.63% | 1.4M | $2.9M | +43,161 (+3.1%) | August 31, 2026 |
| 2 | abrdn Healthcare Investors | 3.63% | 1.4M | $2.9M | — | September 30, 2026 |
| 3 | Vanguard MStar Total Stk Mkt Idx Invest | 2.25% | 887K | $1.8M | — | August 31, 2026 |
| 4 | Fidelity Extended Market Index | 0.41% | 161K | $332,402 | −867 (−0.5%) | August 31, 2026 |
| 5 | iShares Micro-Cap ETF | 0.26% | 104K | $214,990 | −720 (−0.7%) | September 30, 2026 |
| 6 | Fidelity Total Market Index | 0.13% | 51K | $104,316 | — | August 31, 2026 |
| 7 | EA Bridgeway Ultra-Small Company Mkt ETF | 0.13% | 50K | $103,896 | — | September 30, 2026 |
| 8 | Fidelity Series Total Market Index | 0.12% | 47K | $97,525 | — | August 31, 2026 |
| 9 | Goldman Sachs Absolute Ret Trckr Instl | 0.06% | 22K | $44,982 | −1,908 (−8.0%) | June 30, 2026 |
| 10 | Fidelity Nasdaq Composite Index | 0.05% | 19K | $39,039 | — | August 31, 2026 |
| 11 | Vanguard MStar Inst Ttl StkMktIdxInstlPl | 0.05% | 19K | $38,555 | — | August 31, 2026 |
| 12 | Vanguard Balanced Index Inv | 0.03% | 12K | $24,407 | — | August 31, 2026 |
| 13 | Vanguard U.S. Eq Idx £ Acc | 0.03% | 11K | $23,008 | — | August 31, 2026 |
| 14 | 1290 VT Micro Cap K | 0.02% | 6,968 | $14,354 | — | August 31, 2026 |
| 15 | Avantis US Small Cap Equity ETF | 0.01% | 5,403 | $11,130 | — | September 30, 2026 |
| 16 | Dimensional US Core Equity 1 ETF | 0.01% | 5,101 | $10,508 | — | September 24, 2026 |
| 17 | Dimensional International Core Eq Acc | 0.01% | 3,634 | $7,486 | — | August 31, 2026 |
| 18 | JNL/DFA US Small Cap A | 0.01% | 3,288 | $6,773 | — | June 30, 2026 |
| 19 | AST Small-Cap Equity Portfolio | 0.01% | 2,450 | $5,047 | — | August 31, 2026 |
| 20 | Dimensional US Sm Company EUR Acc | <0.01% | 1,816 | $3,741 | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
SERA insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-03-11 | Austin Aerts | Sell | $2.04 | 1,019 | $2,079 |
| 2026-03-11 | Zhenya Lindgardt | Sell | $2.04 | 2,973 | $6,065 |
| 2026-03-11 | Robert Gardner Harrison | Sell | $2.04 | 716 | $1,461 |
| 2026-03-11 | John J Boniface | Sell | $2.04 | 1,517 | $3,095 |
| 2026-03-11 | Paul Kearney | Sell | $2.04 | 1,396 | $2,848 |
| 2026-03-11 | Benjamin Jackson | Sell | $2.04 | 1,027 | $2,095 |
| 2026-03-10 | Austin Aerts | Sell | $1.90 | 6,069 | $11,531 |
| 2026-03-10 | Zhenya Lindgardt | Sell | $1.90 | 22,639 | $43,014 |
| 2026-03-09 | Robert Gardner Harrison | Sell | $1.96 | 3,360 | $6,586 |
| 2026-03-09 | Paul Kearney | Sell | $1.96 | 2,026 | $3,971 |
| 2026-03-09 | Benjamin Jackson | Sell | $1.96 | 3,119 | $6,113 |
| 2026-03-09 | Austin Aerts | Sell | $1.96 | 674 | $1,321 |
| 2026-03-09 | John J Boniface | Sell | $1.96 | 3,038 | $5,954 |
| 2026-03-06 | Sandra Aj Lawrence | Sell | $1.95 | 1,560 | $3,042 |
| 2026-02-24 | Robert Gardner Harrison | Sell | $2.34 | 2,000 | $4,680 |
| 2026-01-27 | Robert Gardner Harrison | Sell | $2.97 | 2,000 | $5,940 |
| 2025-12-30 | Robert Gardner Harrison | Sell | $3.00 | 2,000 | $6,000 |
| 2025-12-10 | Zhenya Lindgardt | Sell | $3.31 | 4,155 | $13,753 |
| 2025-12-10 | Robert Gardner Harrison | Sell | $3.31 | 616 | $2,039 |
| 2025-12-10 | Austin Aerts | Sell | $3.31 | 873 | $2,890 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
SERA shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns SERA
Institutional investors own 51.0% of Sera Prognostics's shares and insiders 12.11%. The largest holder is Baker Bros Advisors LP with 13.94% of the shares (5.5M), as of June 30, 2026. Among the top 20 institutions, 6 added shares and 5 reduced their stake in the latest filings. Short interest is 0.73% of the float, or 10.40 days of average trading volume. The share count rose 176.0% since 2020.
Related: SERA analyst forecast, SERA key metrics. See the SERA stock overview for the latest quote and news.
SERA ownership FAQ
Who owns the most Sera Prognostics stock?
The largest shareholders of Sera Prognostics are Baker Bros Advisors LP (13.94%), Whetstone Capital Advisors, LLC (8.38%), Aberdeen Group PLC (6.98%), Vivo Capital, LLC (4.18%), Vanguard Capital Management, LLC (3.29%).
What percentage of Sera Prognostics is owned by institutions?
Institutions hold 51.0% of Sera Prognostics's shares outstanding; insiders hold 12.11%.
Which funds own Sera Prognostics?
The largest fund holders of Sera Prognostics are abrdn Healthcare Opportunities (3.63%), abrdn Healthcare Investors (3.63%), Vanguard MStar Total Stk Mkt Idx Invest (2.25%), Fidelity Extended Market Index (0.41%), iShares Micro-Cap ETF (0.26%).
What is Sera Prognostics's short interest?
230K shares of Sera Prognostics were sold short, 0.73% of the float; at the average daily volume it would take 10.40 days to cover.
Are insiders buying or selling Sera Prognostics?
Of the latest 20 reported insider transactions in Sera Prognostics (since December 10, 2025), 0 were purchases and 20 were sales.
How many shares of Sera Prognostics are outstanding?
Sera Prognostics has 38.5M shares outstanding, of which 27.7M are in the public float.