Kiniksa Pharmaceuticals, Ltd. (KNSA) Ownership
KNSA ownership summary
as of October 17, 2026- Institutions
- 101.0% of shares outstanding
- Insiders
- 3.51% of shares outstanding
- Shares outstanding
- 48.3M
- Float
- 39.9M shares available to trade
- Short interest
- 9.45% 3.8M shares short
- Days to cover
- 6.69 short interest down 2.5% vs prior month
- Institutions 100.99%
- Insiders 3.51%
KNSA top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | FMR Inc | 8.93% | 7.0M | $547.9M | +147,661 (+2.2%) | June 30, 2026 |
| 2 | Rubric Capital Management LP | 5.13% | 4.0M | $314.3M | +249,800 (+6.7%) | June 30, 2026 |
| 3 | Baker Bros Advisors LP | 3.63% | 2.8M | $222.8M | +8,397 (+0.3%) | June 30, 2026 |
| 4 | BlackRock Inc | 3.51% | 2.7M | $215.3M | +2.3M (+462.9%) | June 30, 2026 |
| 5 | TANG CAPITAL MANAGEMENT LLC | 2.90% | 2.3M | $177.6M | — | June 30, 2026 |
| 6 | Vanguard Portfolio Management, LLC | 2.45% | 1.9M | $150.2M | +145,067 (+8.2%) | June 30, 2026 |
| 7 | Vanguard Capital Management, LLC | 1.74% | 1.4M | $106.9M | +27,747 (+2.1%) | June 30, 2026 |
| 8 | Morgan Stanley - Brokerage Accounts | 1.30% | 1.0M | $79.5M | +13,357 (+1.3%) | June 30, 2026 |
| 9 | Arrowstreet Capital Limited Partnership | 1.23% | 958K | $75.3M | +64,848 (+7.3%) | June 30, 2026 |
| 10 | Spruce Street Capital LP | 1.18% | 918K | $72.2M | +157,007 (+20.6%) | June 30, 2026 |
| 11 | Dimensional Fund Advisors, Inc. | 1.12% | 875K | $68.7M | +62,864 (+7.7%) | June 30, 2026 |
| 12 | Amvescap Plc. | 0.99% | 773K | $60.7M | +745,150 (+2,694.4%) | June 30, 2026 |
| 13 | Driehaus Capital Management LLC | 0.92% | 718K | $56.4M | +106,801 (+17.5%) | June 30, 2026 |
| 14 | State Street Corp | 0.90% | 704K | $55.3M | +627,561 (+818.9%) | June 30, 2026 |
| 15 | Acadian Asset Management LLC | 0.87% | 679K | $53.4M | −657,230 (−49.2%) | June 30, 2026 |
| 16 | Point72 Asset Management, L.P. | 0.85% | 659K | $51.8M | +18,535 (+2.9%) | June 30, 2026 |
| 17 | Rice Hall James & Associates, LLC | 0.80% | 625K | $49.1M | +16,512 (+2.7%) | June 30, 2026 |
| 18 | Pictet Asset Manangement SA | 0.78% | 609K | $47.8M | −14,638 (−2.3%) | June 30, 2026 |
| 19 | Geode Capital Management, LLC | 0.77% | 604K | $47.5M | +559,860 (+1,263.2%) | June 30, 2026 |
| 20 | Jupiter Topco LLC | 0.75% | 586K | $46.1M | +586,177 (0.0%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 17 holders added 5.8M shares and 2 cut 672K.
KNSA top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 1.69% | 1.3M | $103.9M | −1,868 (−0.1%) | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 1.51% | 1.2M | $92.8M | −13,632 (−1.1%) | September 30, 2026 |
| 3 | Fidelity Select Health Care | 1.24% | 970K | $76.2M | +50,000 (+5.4%) | August 31, 2026 |
| 4 | Vanguard Small Cap Index | 1.23% | 958K | $75.3M | +82 (+0.0%) | August 31, 2026 |
| 5 | Strategic Advisers Fidelity US TtlStk | 0.87% | 676K | $53.1M | +28,000 (+4.3%) | August 31, 2026 |
| 6 | Fidelity Select Biotechnology | 0.82% | 638K | $50.1M | — | August 31, 2026 |
| 7 | Fidelity Small Cap Growth | 0.74% | 581K | $45.7M | — | July 31, 2026 |
| 8 | Vanguard MStar Small Cap Growth Indx Inv | 0.71% | 552K | $43.4M | −1,689 (−0.3%) | August 31, 2026 |
| 9 | Fidelity Advisor Health Care I | 0.61% | 474K | $37.3M | +14,000 (+3.0%) | August 31, 2026 |
| 10 | Fidelity Small Cap Index | 0.59% | 463K | $36.4M | +4,295 (+0.9%) | July 31, 2026 |
| 11 | iShares Russell 2000 Growth ETF | 0.55% | 427K | $33.6M | −541 (−0.1%) | September 30, 2026 |
| 12 | Fidelity Advisor Biotechnology I | 0.54% | 418K | $32.8M | — | August 31, 2026 |
| 13 | Pictet-Biotech P USD | 0.51% | 399K | $31.4M | −1,617 (−0.4%) | June 30, 2026 |
| 14 | T. Rowe Price Health Sciences | 0.51% | 394K | $31.0M | +394,000 (0.0%) | August 31, 2026 |
| 15 | Oberweis Micro-Cap | 0.50% | 390K | $30.6M | +84,600 (+27.7%) | June 30, 2026 |
| 16 | Victory Trivalent International Sm-Cp I | 0.43% | 333K | $26.1M | — | June 30, 2026 |
| 17 | Xtrackers MSCI USA Swap ETF 1C | 0.38% | 300K | $23.6M | +136,043 (+83.1%) | December 31, 2025 |
| 18 | MFS New Discovery I | 0.38% | 298K | $23.4M | — | August 31, 2026 |
| 19 | Fidelity Small Cap Growth K6 | 0.37% | 292K | $22.9M | — | July 31, 2026 |
| 20 | Heptagon Driehaus US Micro Cap Eq C$ Acc | 0.36% | 283K | $22.2M | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
KNSA insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-09 | Ross Moat | Sell | $46.69 | 1,703 | $79,513 |
| 2026-04-09 | Michael R Megna | Sell | $46.69 | 6,625 | $309,321 |
| 2026-04-06 | Barry D Quart | Sell | $50.00 | 6,901 | $345,050 |
| 2026-04-06 | Ross Moat | Sell | $48.58 | 2,367 | $114,989 |
| 2026-04-06 | Sanj K Patel | Sell | $50.01 | 7,278 | $363,973 |
| 2026-02-12 | Barry D Quart | Sell | $45.00 | 2,690 | $121,050 |
| 2026-02-10 | Barry D Quart | Sell | $45.00 | 110 | $4,950 |
| 2026-02-09 | Mark Ragosa | Sell | $43.28 | 17,845 | $772,332 |
| 2026-02-04 | Barry D Quart | Sell | $45.02 | 2,602 | $117,142 |
| 2026-02-03 | Barry D Quart | Sell | $45.27 | 12,528 | $567,143 |
| 2026-02-02 | Barry D Quart | Sell | $45.00 | 830 | $37,350 |
| 2026-01-08 | Mark Ragosa | Sell | $41.89 | 12,000 | $502,680 |
| 2025-12-15 | Barry D Quart | Sell | $41.51 | 20,129 | $835,555 |
| 2025-12-15 | Eben Tessari | Sell | $41.56 | 12,048 | $500,715 |
| 2025-12-08 | Mark Ragosa | Sell | $41.49 | 42,841 | $1.8M |
| 2025-11-26 | Eben Tessari | Sell | $42.89 | 200 | $8,578 |
| 2025-11-17 | Eben Tessari | Sell | $41.24 | 12,470 | $514,263 |
| 2025-11-12 | Mark Ragosa | Sell | $40.94 | 19,900 | $814,706 |
| 2025-10-31 | John F Paolini | Sell | $37.14 | 82,542 | $3.1M |
| 2025-10-28 | Mark Ragosa | Sell | $41.00 | 100 | $4,100 |
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.
KNSA shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns KNSA
Institutional investors own 101.0% of Kiniksa Pharmaceuticals's shares and insiders 3.51%. The largest holder is FMR Inc with 8.93% of the shares (7.0M), as of June 30, 2026. Among the top 20 institutions, 17 added shares and 2 reduced their stake in the latest filings. Short interest is 9.45% of the float, or 6.69 days of average trading volume. The share count rose 143.3% since 2017.
Related: KNSA analyst forecast, KNSA key metrics. See the KNSA stock overview for the latest quote and news.
KNSA ownership FAQ
Who owns the most Kiniksa Pharmaceuticals stock?
The largest shareholders of Kiniksa Pharmaceuticals are FMR Inc (8.93%), Rubric Capital Management LP (5.13%), Baker Bros Advisors LP (3.63%), BlackRock Inc (3.51%), TANG CAPITAL MANAGEMENT LLC (2.90%).
What percentage of Kiniksa Pharmaceuticals is owned by institutions?
Institutions hold 101.0% of Kiniksa Pharmaceuticals's shares outstanding; insiders hold 3.51%.
Which funds own Kiniksa Pharmaceuticals?
The largest fund holders of Kiniksa Pharmaceuticals are Vanguard MStar Total Stk Mkt Idx Invest (1.69%), iShares Russell 2000 ETF (1.51%), Fidelity Select Health Care (1.24%), Vanguard Small Cap Index (1.23%), Strategic Advisers Fidelity US TtlStk (0.87%).
What is Kiniksa Pharmaceuticals's short interest?
3.8M shares of Kiniksa Pharmaceuticals were sold short, 9.45% of the float; at the average daily volume it would take 6.69 days to cover.
Are insiders buying or selling Kiniksa Pharmaceuticals?
Of the latest 20 reported insider transactions in Kiniksa Pharmaceuticals (since October 28, 2025), 0 were purchases and 20 were sales.
How many shares of Kiniksa Pharmaceuticals are outstanding?
Kiniksa Pharmaceuticals has 48.3M shares outstanding, of which 39.9M are in the public float.