Personalis, Inc. (PSNL) Ownership
PSNL ownership summary
as of October 18, 2026- Institutions
- 66.9% of shares outstanding
- Insiders
- 26.15% of shares outstanding
- Shares outstanding
- 106.8M
- Float
- 86.4M shares available to trade
- Short interest
- 12.32% 8.4M shares short
- Days to cover
- 3.81 short interest up 2.0% vs prior month
- Institutions 66.88%
- Insiders 26.15%
- Other investors 6.97%
PSNL top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Merck & Co Inc | 13.15% | 14.0M | $219.8M | — | June 30, 2026 |
| 2 | ARK Investment Management LLC | 7.74% | 8.3M | $129.4M | +327,227 (+4.1%) | June 30, 2026 |
| 3 | BlackRock Inc | 6.63% | 7.1M | $110.8M | +1.7M (+31.4%) | June 30, 2026 |
| 4 | Lightspeed Management Co LLC | 5.71% | 6.1M | $95.5M | −2.1M (−25.2%) | June 30, 2026 |
| 5 | Ameriprise Financial Inc | 5.70% | 6.1M | $95.3M | −1.5M (−19.8%) | June 30, 2026 |
| 6 | Deep Track Capital, LP | 3.75% | 4.0M | $62.6M | +1.0M (+33.3%) | June 30, 2026 |
| 7 | Aberdeen Group PLC | 3.51% | 3.7M | $58.6M | +258,982 (+7.4%) | June 30, 2026 |
| 8 | Vanguard Capital Management, LLC | 2.82% | 3.0M | $47.1M | +141,687 (+4.9%) | June 30, 2026 |
| 9 | Casdin Capital, LLC | 2.39% | 2.5M | $39.9M | +950,000 (+59.4%) | June 30, 2026 |
| 10 | Kennedy Capital Management Inc | 2.21% | 2.4M | $37.0M | +180,710 (+8.3%) | June 30, 2026 |
| 11 | Geode Capital Management, LLC | 1.71% | 1.8M | $28.5M | +524,790 (+40.4%) | June 30, 2026 |
| 12 | Bank of America Corp | 1.70% | 1.8M | $28.5M | +1.7M (+1,535.6%) | June 30, 2026 |
| 13 | AIGH Capital Management, LLC | 1.61% | 1.7M | $26.8M | −1.2M (−40.9%) | June 30, 2026 |
| 14 | Blue Water Life Science Advisors, LLC | 1.57% | 1.7M | $26.2M | — | June 30, 2026 |
| 15 | Dimensional Fund Advisors, Inc. | 1.40% | 1.5M | $23.4M | +430,735 (+40.4%) | June 30, 2026 |
| 16 | State Street Corp | 1.39% | 1.5M | $23.3M | +352,907 (+31.1%) | June 30, 2026 |
| 17 | Morgan Stanley - Brokerage Accounts | 1.19% | 1.3M | $19.9M | +1.0M (+435.6%) | June 30, 2026 |
| 18 | The Goldman Sachs Group Inc | 0.87% | 931K | $14.6M | +193,899 (+26.3%) | June 30, 2026 |
| 19 | HRT FINANCIAL LLC | 0.87% | 931K | $14.6M | +721,925 (+345.6%) | June 30, 2026 |
| 20 | Nuveen, LLC | 0.71% | 753K | $11.8M | +409,484 (+119.2%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 15 holders added 9.9M shares and 3 cut 4.8M.
PSNL top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | ARK Genomic Revolution ETF | 6.23% | 6.7M | $104.2M | +16,276 (+0.2%) | September 30, 2026 |
| 2 | abrdn Healthcare Investors | 2.04% | 2.2M | $34.0M | — | September 30, 2026 |
| 3 | Vanguard MStar Total Stk Mkt Idx Invest | 2.01% | 2.1M | $33.5M | — | August 31, 2026 |
| 4 | iShares Russell 2000 ETF | 1.76% | 1.9M | $29.4M | −21,632 (−1.1%) | September 30, 2026 |
| 5 | Columbia Acorn Inst | 1.26% | 1.3M | $21.1M | −401,333 (−23.0%) | August 31, 2026 |
| 6 | abrdn Life Sciences Investors | 1.22% | 1.3M | $20.4M | −134,868 (−9.4%) | September 30, 2026 |
| 7 | Columbia Small Cap Growth Inst | 0.88% | 938K | $14.7M | — | August 31, 2026 |
| 8 | Fidelity Small Cap Index | 0.70% | 743K | $11.6M | +6,947 (+0.9%) | July 31, 2026 |
| 9 | T. Rowe Price New Horizons | 0.66% | 701K | $11.0M | — | September 30, 2026 |
| 10 | iShares Russell 2000 Value ETF | 0.64% | 681K | $10.7M | +1,032 (+0.2%) | September 30, 2026 |
| 11 | AZ Fd 1 - AZ Eq - Amer Opps A-EUR Acc | 0.54% | 582K | $9.1M | −80,790 (−12.2%) | August 31, 2026 |
| 12 | Nuveen Quant Small Cap Equity R6 | 0.53% | 570K | $8.9M | — | August 31, 2026 |
| 13 | iShares Biotechnology ETF | 0.53% | 562K | $8.8M | −4,256 (−0.8%) | September 30, 2026 |
| 14 | CT (Lux) American Smaller Com 9U USD | 0.53% | 562K | $8.8M | −1.2M (−67.6%) | August 31, 2026 |
| 15 | Vanguard Russell 2000 ETF | 0.39% | 421K | $6.6M | +31,698 (+8.1%) | September 30, 2026 |
| 16 | RBC Private U.S. Small-Cap Eqty Pool F | 0.36% | 387K | $6.0M | +2,047 (+0.5%) | September 30, 2026 |
| 17 | Schwab US Small-Cap ETF™ | 0.33% | 352K | $5.5M | +234 (+0.1%) | September 30, 2026 |
| 18 | Fidelity Extended Market Index | 0.32% | 341K | $5.3M | −5,219 (−1.5%) | August 31, 2026 |
| 19 | ARK Genomic Revolution ETF A USD Acc | 0.30% | 321K | $5.0M | — | September 30, 2026 |
| 20 | DFA US Small Cap I | 0.25% | 264K | $4.1M | −2,675 (−1.0%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
PSNL insider transactions
latest 8| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-01-22 | Aaron Tachibana | Sell | $11.50 | 1,201 | $13,812 |
| 2025-11-25 | Aaron Tachibana | Sell | $10.78 | 103,668 | $1.1M |
| 2025-11-03 | Christopher M Hall | Sell | $8.99 | 29,612 | $266,212 |
| 2025-07-28 | Aaron Tachibana | Sell | $6.57 | 641 | $4,211 |
| 2025-07-28 | Richard Chen | Sell | $6.57 | 452 | $2,970 |
| 2025-05-16 | Aaron Tachibana | Sell | $4.95 | 1,291 | $6,390 |
| 2025-05-16 | Richard Chen | Sell | $4.95 | 910 | $4,504 |
| 2025-05-16 | Stephen Michael Moore | Sell | $4.95 | 1,675 | $8,291 |
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.
PSNL shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns PSNL
Institutional investors own 66.9% of Personalis's shares and insiders 26.15%. The largest holder is Merck & Co Inc with 13.15% of the shares (14.0M), as of June 30, 2026. Among the top 20 institutions, 15 added shares and 3 reduced their stake in the latest filings. Short interest is 12.32% of the float, or 3.81 days of average trading volume. The share count rose 2,976.0% since 2017.
Related: PSNL analyst forecast, PSNL key metrics. See the PSNL stock overview for the latest quote and news.
PSNL ownership FAQ
Who owns the most Personalis stock?
The largest shareholders of Personalis are Merck & Co Inc (13.15%), ARK Investment Management LLC (7.74%), BlackRock Inc (6.63%), Lightspeed Management Co LLC (5.71%), Ameriprise Financial Inc (5.70%).
What percentage of Personalis is owned by institutions?
Institutions hold 66.9% of Personalis's shares outstanding; insiders hold 26.15%.
Which funds own Personalis?
The largest fund holders of Personalis are ARK Genomic Revolution ETF (6.23%), abrdn Healthcare Investors (2.04%), Vanguard MStar Total Stk Mkt Idx Invest (2.01%), iShares Russell 2000 ETF (1.76%), Columbia Acorn Inst (1.26%).
What is Personalis's short interest?
8.4M shares of Personalis were sold short, 12.32% of the float; at the average daily volume it would take 3.81 days to cover.
Are insiders buying or selling Personalis?
Of the latest 8 reported insider transactions in Personalis (since May 16, 2025), 0 were purchases and 8 were sales.
How many shares of Personalis are outstanding?
Personalis has 106.8M shares outstanding, of which 86.4M are in the public float.