Keros Therapeutics, Inc. (KROS) Ownership
KROS ownership summary
as of October 18, 2026- Institutions
- 95.0% of shares outstanding
- Insiders
- 3.96% of shares outstanding
- Shares outstanding
- 19.8M
- Float
- 17.8M shares available to trade
- Short interest
- 6.67% 1.1M shares short
- Days to cover
- 6.41 short interest down 14.4% vs prior month
- Institutions 95.05%
- Insiders 3.96%
- Other investors 0.99%
KROS top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Nantahala Capital Management, LLC | 14.23% | 2.8M | $30.1M | +1.5M (+107.4%) | June 30, 2026 |
| 2 | BlackRock Inc | 14.09% | 2.8M | $29.8M | +382,424 (+15.9%) | June 30, 2026 |
| 3 | AQR Capital Management LLC | 4.88% | 968K | $10.3M | +561,296 (+138.1%) | June 30, 2026 |
| 4 | Vanguard Capital Management, LLC | 4.20% | 834K | $8.9M | +2,175 (+0.3%) | June 30, 2026 |
| 5 | Orbimed Advisors LLC | 3.83% | 759K | $8.1M | — | June 30, 2026 |
| 6 | Federated Hermes Inc | 3.53% | 700K | $7.5M | +11,198 (+1.6%) | June 30, 2026 |
| 7 | Vanguard Portfolio Management, LLC | 3.29% | 653K | $7.0M | −29,408 (−4.3%) | June 30, 2026 |
| 8 | Mackenzie Investments | 3.17% | 628K | $6.7M | +475,988 (+312.2%) | June 30, 2026 |
| 9 | Madison Avenue Partners, LP | 3.16% | 627K | $6.7M | — | June 30, 2026 |
| 10 | Qube Research & Technologies | 3.07% | 609K | $6.5M | −116,089 (−16.0%) | June 30, 2026 |
| 11 | Jacobs Levy Equity Management, Inc. | 3.05% | 605K | $6.5M | −100,626 (−14.3%) | June 30, 2026 |
| 12 | State Street Corp | 2.73% | 541K | $5.8M | −20,537 (−3.7%) | June 30, 2026 |
| 13 | Geode Capital Management, LLC | 2.58% | 511K | $5.4M | −170,619 (−25.0%) | June 30, 2026 |
| 14 | Dimensional Fund Advisors, Inc. | 2.32% | 461K | $4.9M | +139,181 (+43.3%) | June 30, 2026 |
| 15 | Citadel Advisors Llc | 2.00% | 396K | $4.2M | −10,568 (−2.6%) | June 30, 2026 |
| 16 | Renaissance Technologies Corp | 1.81% | 359K | $3.8M | −94,396 (−20.8%) | June 30, 2026 |
| 17 | D. E. Shaw & Co LP | 1.35% | 267K | $2.9M | −242,148 (−47.5%) | June 30, 2026 |
| 18 | Bridgeway Capital Management, LLC | 1.34% | 265K | $2.8M | +70,000 (+35.9%) | June 30, 2026 |
| 19 | Nuveen, LLC | 1.25% | 248K | $2.6M | −14,319 (−5.5%) | June 30, 2026 |
| 20 | ADAR1 Capital Management LLC | 1.24% | 247K | $2.6M | +149,500 (+153.6%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 9 holders added 3.3M shares and 9 cut 799K.
KROS top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 3.00% | 595K | $6.3M | — | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 2.41% | 477K | $5.1M | −5,504 (−1.1%) | September 30, 2026 |
| 3 | BlackRock Advantage Small Cap Core Instl | 2.31% | 459K | $4.9M | +42,279 (+10.2%) | August 31, 2026 |
| 4 | Federated Hermes MDT Small Cap Core IS | 1.93% | 382K | $4.1M | — | June 30, 2026 |
| 5 | Canada Life US Small-Mid Cap Growth F | 1.47% | 292K | $3.1M | — | July 31, 2026 |
| 6 | Vanguard Strategic Small-Cap Equity Inv | 1.30% | 259K | $2.8M | +47,695 (+22.6%) | June 30, 2026 |
| 7 | Fidelity Small Cap Index | 1.01% | 200K | $2.1M | +1,441 (+0.7%) | July 31, 2026 |
| 8 | Nuveen Quant Small Cap Equity R6 | 0.96% | 190K | $2.0M | — | August 31, 2026 |
| 9 | iShares Russell 2000 Value ETF | 0.88% | 175K | $1.9M | +266 (+0.2%) | September 30, 2026 |
| 10 | Vanguard Explorer Inv | 0.86% | 171K | $1.8M | — | June 30, 2026 |
| 11 | Xtrackers S&P 500 Swap ETF 1C | 0.85% | 169K | $1.8M | +169,391 (0.0%) | December 31, 2025 |
| 12 | Bridge Builder Small/Mid Cap Value | 0.82% | 162K | $1.7M | +149,300 (+1,149.0%) | September 30, 2026 |
| 13 | iShares Biotechnology ETF | 0.72% | 142K | $1.5M | −1,072 (−0.7%) | September 30, 2026 |
| 14 | Federated Hermes MDT Small Cap Growth IS | 0.59% | 116K | $1.2M | — | June 30, 2026 |
| 15 | EA Bridgeway Omni Small-Cap Value ETF | 0.54% | 107K | $1.1M | — | September 30, 2026 |
| 16 | iShares U.S. Small-Cap Eq Fac ETF | 0.54% | 106K | $1.1M | — | September 30, 2026 |
| 17 | Vanguard Russell 2000 ETF | 0.53% | 106K | $1.1M | +3,136 (+3.1%) | August 31, 2026 |
| 18 | DFA US Small Cap Value I | 0.53% | 106K | $1.1M | −36,345 (−25.6%) | August 31, 2026 |
| 19 | Schwab US Small-Cap ETF™ | 0.53% | 104K | $1.1M | +63 (+0.1%) | September 30, 2026 |
| 20 | BlackRock Advantage Small Cap Gr Instl | 0.42% | 83K | $888,287 | +1,432 (+1.7%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
KROS insider transactions
latest 3| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-15 | Jean Jacques Bienaime | Buy | $11.70 | 1,000 | $11,700 |
| 2025-10-15 | Adar1 Capital Management, Llc | Sell | $17.75 | 5,389,264 | $95.7M |
| 2025-10-15 | Pontifax Management 4 G.P. (20 | Sell | $17.75 | 4,787,331 | $85.0M |
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.
KROS shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns KROS
Institutional investors own 95.0% of Keros Therapeutics's shares and insiders 3.96%. The largest holder is Nantahala Capital Management, LLC with 14.23% of the shares (2.8M), as of June 30, 2026. Among the top 20 institutions, 9 added shares and 9 reduced their stake in the latest filings. Short interest is 6.67% of the float, or 6.41 days of average trading volume. The share count rose 206.2% since 2019.
Related: KROS analyst forecast, KROS key metrics. See the KROS stock overview for the latest quote and news.
KROS ownership FAQ
Who owns the most Keros Therapeutics stock?
The largest shareholders of Keros Therapeutics are Nantahala Capital Management, LLC (14.23%), BlackRock Inc (14.09%), AQR Capital Management LLC (4.88%), Vanguard Capital Management, LLC (4.20%), Orbimed Advisors LLC (3.83%).
What percentage of Keros Therapeutics is owned by institutions?
Institutions hold 95.0% of Keros Therapeutics's shares outstanding; insiders hold 3.96%.
Which funds own Keros Therapeutics?
The largest fund holders of Keros Therapeutics are Vanguard MStar Total Stk Mkt Idx Invest (3.00%), iShares Russell 2000 ETF (2.41%), BlackRock Advantage Small Cap Core Instl (2.31%), Federated Hermes MDT Small Cap Core IS (1.93%), Canada Life US Small-Mid Cap Growth F (1.47%).
What is Keros Therapeutics's short interest?
1.1M shares of Keros Therapeutics were sold short, 6.67% of the float; at the average daily volume it would take 6.41 days to cover.
Are insiders buying or selling Keros Therapeutics?
Of the latest 3 reported insider transactions in Keros Therapeutics (since October 15, 2025), 1 were purchases and 2 were sales.
How many shares of Keros Therapeutics are outstanding?
Keros Therapeutics has 19.8M shares outstanding, of which 17.8M are in the public float.