Prime Medicine, Inc. (PRME) Ownership
PRME ownership summary
as of October 17, 2026- Institutions
- 71.0% of shares outstanding
- Insiders
- 20.30% of shares outstanding
- Shares outstanding
- 181.4M
- Float
- 112.2M shares available to trade
- Short interest
- 22.64% 32.1M shares short
- Days to cover
- 9.99 short interest down 0.0% vs prior month
- Institutions 70.98%
- Insiders 20.30%
- Other investors 8.72%
PRME top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Alphabet Inc | 9.13% | 16.6M | $57.5M | — | June 30, 2026 |
| 2 | BlackRock Inc | 5.29% | 9.6M | $33.3M | +1.1M (+12.9%) | June 30, 2026 |
| 3 | ARK Investment Management LLC | 4.60% | 8.3M | $29.0M | +2.1M (+33.6%) | June 30, 2026 |
| 4 | State Street Corp | 4.18% | 7.6M | $26.3M | +1.2M (+19.4%) | June 30, 2026 |
| 5 | T. Rowe Price Investment Management,Inc. | 2.89% | 5.2M | $18.2M | −244,561 (−4.5%) | June 30, 2026 |
| 6 | Vanguard Capital Management, LLC | 2.49% | 4.5M | $15.7M | +48,478 (+1.1%) | June 30, 2026 |
| 7 | Balyasny Asset Management LLC | 2.19% | 4.0M | $13.8M | −154,283 (−3.7%) | June 30, 2026 |
| 8 | The Goldman Sachs Group Inc | 1.89% | 3.4M | $11.9M | +2.5M (+253.5%) | June 30, 2026 |
| 9 | Casdin Capital, LLC | 1.75% | 3.2M | $11.0M | — | June 30, 2026 |
| 10 | Woodline Partners LP | 1.66% | 3.0M | $10.4M | +591 (+0.0%) | June 30, 2026 |
| 11 | UBS Group AG | 1.54% | 2.8M | $9.7M | −93,729 (−3.2%) | June 30, 2026 |
| 12 | Geode Capital Management, LLC | 1.50% | 2.7M | $9.4M | −31,254 (−1.1%) | June 30, 2026 |
| 13 | Sumitomo Mitsui Trust Group Inc | 1.33% | 2.4M | $8.4M | −527,809 (−17.9%) | June 30, 2026 |
| 14 | Amova Asset Management Americas, Inc | 1.33% | 2.4M | $8.4M | −533,775 (−18.2%) | June 30, 2026 |
| 15 | Citadel Advisors Llc | 1.13% | 2.1M | $7.1M | +1.7M (+510.8%) | June 30, 2026 |
| 16 | ADAR1 Capital Management LLC | 1.10% | 2.0M | $6.9M | +24,270 (+1.2%) | June 30, 2026 |
| 17 | FMR Inc | 0.97% | 1.8M | $6.1M | −7,592 (−0.4%) | June 30, 2026 |
| 18 | Two Sigma Investments LLC | 0.84% | 1.5M | $5.3M | −48,300 (−3.1%) | June 30, 2026 |
| 19 | Redmile Group, LLC | 0.77% | 1.4M | $4.8M | −201,200 (−12.6%) | June 30, 2026 |
| 20 | Farallon Capital Management, L.L.C. | 0.68% | 1.2M | $4.3M | — | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 8 holders added 8.7M shares and 9 cut 1.8M.
PRME top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | ARK Genomic Revolution ETF | 4.20% | 7.6M | $26.4M | +18,620 (+0.2%) | September 30, 2026 |
| 2 | State Street® SPDR® S&P® Biotech ETF | 2.01% | 3.6M | $12.6M | −69,600 (−1.9%) | September 30, 2026 |
| 3 | Vanguard MStar Total Stk Mkt Idx Invest | 1.72% | 3.1M | $10.8M | — | August 31, 2026 |
| 4 | ARK Venture D | 1.37% | 2.5M | $8.6M | +1.4M (+129.9%) | April 30, 2026 |
| 5 | iShares Russell 2000 ETF | 1.34% | 2.4M | $8.5M | −28,096 (−1.1%) | September 30, 2026 |
| 6 | Amova ARK Pstv Chg Innovt P JPY Acc | 1.33% | 2.4M | $8.4M | −160,079 (−6.2%) | August 31, 2026 |
| 7 | T. Rowe Price Small-Cap Stock | 0.67% | 1.2M | $4.2M | −811 (−0.1%) | August 31, 2026 |
| 8 | Fidelity Small Cap Index | 0.56% | 1.0M | $3.6M | +2,822 (+0.3%) | July 31, 2026 |
| 9 | T. Rowe Price Small-Cap Value | 0.55% | 995K | $3.5M | −9,122 (−0.9%) | August 31, 2026 |
| 10 | T. Rowe Price Instl Small-Cap Stock | 0.43% | 783K | $2.7M | — | August 31, 2026 |
| 11 | iShares Russell 2000 Growth ETF | 0.43% | 772K | $2.7M | −977 (−0.1%) | September 30, 2026 |
| 12 | iShares Biotechnology ETF | 0.41% | 740K | $2.6M | −5,608 (−0.8%) | September 30, 2026 |
| 13 | BlackRock Advantage Small Cap Core Instl | 0.39% | 716K | $2.5M | — | August 31, 2026 |
| 14 | Selectra J. Lamarck Biotech A | 0.37% | 670K | $2.3M | +10,000 (+1.5%) | September 30, 2026 |
| 15 | Schwab US Small-Cap ETF™ | 0.35% | 630K | $2.2M | +423 (+0.1%) | September 30, 2026 |
| 16 | Fidelity Extended Market Index | 0.32% | 578K | $2.0M | +109,336 (+23.3%) | August 31, 2026 |
| 17 | Vanguard Russell 2000 ETF | 0.30% | 541K | $1.9M | +13,916 (+2.6%) | August 31, 2026 |
| 18 | ARK Genomic Revolution ETF A USD Acc | 0.23% | 425K | $1.5M | — | September 30, 2026 |
| 19 | JPM Thmtcs Gentc Thrps C2 dist USD | 0.19% | 351K | $1.2M | +3,939 (+1.1%) | August 31, 2026 |
| 20 | Vanguard Health Care ETF | 0.17% | 316K | $1.1M | +1,380 (+0.4%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
PRME insider transactions
latest 4| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2025-08-01 | Arch Venture Partners Xii, Llc | Buy | $3.30 | 3,030,300 | $10.0M |
| 2025-06-23 | David R Liu | Buy | $2.16 | 21,000 | $45,360 |
| 2025-06-16 | David R Liu | Buy | $1.49 | 21,000 | $31,290 |
| 2025-06-11 | David R Liu | Buy | $1.60 | 21,000 | $33,600 |
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.
PRME shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns PRME
Institutional investors own 71.0% of Prime Medicine's shares and insiders 20.30%. The largest holder is Alphabet Inc with 9.13% of the shares (16.6M), as of June 30, 2026. Among the top 20 institutions, 8 added shares and 9 reduced their stake in the latest filings. Short interest is 22.64% of the float, or 9.99 days of average trading volume. The share count rose 55.4% since 2019.
Related: PRME analyst forecast, PRME key metrics. See the PRME stock overview for the latest quote and news.
PRME ownership FAQ
Who owns the most Prime Medicine stock?
The largest shareholders of Prime Medicine are Alphabet Inc (9.13%), BlackRock Inc (5.29%), ARK Investment Management LLC (4.60%), State Street Corp (4.18%), T. Rowe Price Investment Management,Inc. (2.89%).
What percentage of Prime Medicine is owned by institutions?
Institutions hold 71.0% of Prime Medicine's shares outstanding; insiders hold 20.30%.
Which funds own Prime Medicine?
The largest fund holders of Prime Medicine are ARK Genomic Revolution ETF (4.20%), State Street® SPDR® S&P® Biotech ETF (2.01%), Vanguard MStar Total Stk Mkt Idx Invest (1.72%), ARK Venture D (1.37%), iShares Russell 2000 ETF (1.34%).
What is Prime Medicine's short interest?
32.1M shares of Prime Medicine were sold short, 22.64% of the float; at the average daily volume it would take 9.99 days to cover.
Are insiders buying or selling Prime Medicine?
Of the latest 4 reported insider transactions in Prime Medicine (since June 11, 2025), 4 were purchases and 0 were sales.
How many shares of Prime Medicine are outstanding?
Prime Medicine has 181.4M shares outstanding, of which 112.2M are in the public float.