Who owns Kiniksa Pharmaceuticals, Ltd. (KNSA)
Which tracked institutional funds hold KNSA, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See KNSA company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
79 tracked funds added or opened KNSA while 47 trimmed or exited it between 2025-Q4 and 2026-Q1 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
KNSA’s largest tracked holder by dollar value, FMR LLC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes KNSA more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in KNSA divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 229 tracked filers holding KNSA, 117 increased or opened the position and 124 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in KNSA between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 21
- VANGUARD PORTFOLIO MANAGEMENT LLC$85M
- VANGUARD CAPITAL MANAGEMENT LLC$64M
- BALYASNY ASSET MANAGEMENT L.P.$24M
- Penn Capital Management Company, LLC$15M
- NEW YORK STATE COMMON RETIREMENT FUND$10M
- Brevan Howard Capital Management LP$3M
Full exits 16
- VANGUARD GROUP INC$126M
- Fairmount Funds Management LLC$54M
- Logos Global Management LP$14M
- JANE STREET GROUP, LLC$10M
- Hillsdale Investment Management Inc.$9M
- TWO SIGMA ADVISERS, LP$9M
Largest adds
- FMR LLC$257M
- Rubric Capital Management LP$43M
- BANK OF AMERICA CORP /DE/$26M
- BAKER BROS. ADVISORS LP$20M
- Spruce Street Capital LP$19M
- JANUS HENDERSON GROUP PLC$17M
Largest trims
- GOLDMAN SACHS GROUP INC$26M
- Parkman Healthcare Partners LLC$15M
- MORGAN STANLEY$8M
- CITADEL ADVISORS LLC$8M
- MILLENNIUM MANAGEMENT LLC$7M
- ACADIAN ASSET MANAGEMENT LLC$6M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 6,751,821 | $325M | 13.7% | 2026-Q1 |
| Rubric Capital Management LP added | 3,750,000 | $181M | 7.6% | 2026-Q1 |
| BAKER BROS. ADVISORS LP | 2,826,246 | $136M | 5.7% | 2026-Q1 |
| TANG CAPITAL MANAGEMENT LLC | 2,259,889 | $109M | 4.6% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 1,766,268 | $85M | 3.6% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 1,336,313 | $64M | 2.7% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 1,333,093 | $64M | 2.7% | 2026-Q1 |
| MORGAN STANLEY trimmed | 997,786 | $48M | 2.0% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 959,257 | $46M | 1.9% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 892,666 | $43M | 1.8% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 811,922 | $39M | 1.6% | 2026-Q1 |
| Spruce Street Capital LP added | 761,063 | $37M | 1.5% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 735,940 | $35M | 1.5% | 2026-Q1 |
| Qube Research & Technologies Ltd trimmed | 686,853 | $33M | 1.4% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 649,629 | $31M | 1.3% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 647,731 | $31M | 1.3% | 2026-Q1 |
| Point72 Asset Management, L.P. trimmed | 640,958 | $31M | 1.3% | 2026-Q1 |
| SG Americas Securities, LLC added | 640,179 | $31M | 1.3% | 2026-Q1 |
| Pictet Asset Management Holding SA trimmed | 623,288 | $30M | 1.3% | 2026-Q1 |
| Driehaus Capital Management LLC trimmed | 611,398 | $29M | 1.2% | 2026-Q1 |
| RICE HALL JAMES & ASSOCIATES, LLC added | 608,416 | $29M | 1.2% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 564,420 | $27M | 1.1% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 523,691 | $25M | 1.1% | 2026-Q1 |
| Soleus Capital Management, L.P. trimmed | 521,353 | $25M | 1.1% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. added | 598,888 | $25M | 1.0% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 506,521 | $24M | 1.0% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. added | 499,792 | $24M | 1.0% | 2026-Q1 |
| BlackRock, Inc. added | 486,737 | $23M | 1.0% | 2026-Q1 |
| JANUS HENDERSON GROUP PLC added | 481,023 | $23M | 1.0% | 2026-Q1 |
| CITADEL ADVISORS LLC trimmed | 474,750 | $23M | 1.0% | 2026-Q1 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ added | 438,002 | $21M | 0.9% | 2026-Q1 |
| Fisher Asset Management, LLC added | 428,972 | $21M | 0.9% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP trimmed | 420,914 | $20M | 0.9% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 383,811 | $18M | 0.8% | 2026-Q1 |
| Aberdeen Group plc trimmed | 373,634 | $18M | 0.8% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 369,854 | $18M | 0.7% | 2026-Q1 |
| NOMURA HOLDINGS INC trimmed | 342,939 | $17M | 0.7% | 2026-Q1 |
| OBERWEIS ASSET MANAGEMENT INC/ added | 318,634 | $15M | 0.6% | 2026-Q1 |
| ArrowMark Colorado Holdings LLC trimmed | 316,956 | $15M | 0.6% | 2026-Q1 |
| MARSHALL WACE, LLP added | 305,371 | $15M | 0.6% | 2026-Q1 |
| Penn Capital Management Company, LLC new | 301,993 | $15M | 0.6% | 2026-Q1 |
| SEI INVESTMENTS CO added | 284,005 | $14M | 0.6% | 2026-Q1 |
| BRAIDWELL LP trimmed | 272,522 | $13M | 0.6% | 2026-Q1 |
| Parkman Healthcare Partners LLC trimmed | 259,184 | $12M | 0.5% | 2026-Q1 |
| ESSEX INVESTMENT MANAGEMENT CO LLC trimmed | 249,278 | $12M | 0.5% | 2026-Q1 |
| NEW YORK STATE COMMON RETIREMENT FUND added | 209,617 | $10M | 0.4% | 2026-Q1 |
| Granahan Investment Management, LLC trimmed | 209,256 | $10M | 0.4% | 2026-Q1 |
| CASTLEARK MANAGEMENT LLC trimmed | 181,512 | $9M | 0.4% | 2026-Q1 |
| PEREGRINE CAPITAL MANAGEMENT LLC trimmed | 181,360 | $9M | 0.4% | 2026-Q1 |
| ORBIMED ADVISORS LLC trimmed | 180,599 | $9M | 0.4% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 174,901 | $8M | 0.4% | 2026-Q1 |
| Rockefeller Capital Management L.P. trimmed | 173,438 | $8M | 0.4% | 2026-Q1 |
| Squarepoint Ops LLC added | 158,093 | $8M | 0.3% | 2026-Q1 |
| Trexquant Investment LP trimmed | 135,280 | $7M | 0.3% | 2026-Q1 |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC trimmed | 134,516 | $6M | 0.3% | 2026-Q1 |
| Man Group plc added | 127,186 | $6M | 0.3% | 2026-Q1 |
| Linden Thomas Advisory Services, LLC added | 121,777 | $6M | 0.2% | 2026-Q1 |
| Voleon Capital Management LP trimmed | 120,385 | $6M | 0.2% | 2026-Q1 |
| SILVERCREST ASSET MANAGEMENT GROUP LLC trimmed | 114,289 | $6M | 0.2% | 2026-Q1 |
| NORDEA INVESTMENT MANAGEMENT AB trimmed | 106,635 | $5M | 0.2% | 2026-Q1 |
| Universal- Beteiligungs- und Servicegesellschaft mbH added | 104,654 | $5M | 0.2% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 107,017 | $5M | 0.2% | 2026-Q1 |
| GLOBEFLEX CAPITAL L P | 93,396 | $4M | 0.2% | 2026-Q1 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND trimmed | 88,600 | $4M | 0.2% | 2026-Q1 |
| PDT Partners, LLC trimmed | 80,263 | $4M | 0.2% | 2026-Q1 |
| STATE STREET CORP added | 76,633 | $4M | 0.2% | 2026-Q1 |
| Swiss National Bank added | 71,500 | $3M | 0.1% | 2026-Q1 |
| Legato Capital Management LLC added | 70,805 | $3M | 0.1% | 2026-Q1 |
| UBS Group AG trimmed | 69,700 | $3M | 0.1% | 2026-Q1 |
| Hennion & Walsh Asset Management, Inc. trimmed | 67,341 | $3M | 0.1% | 2026-Q1 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE added | 63,346 | $3M | 0.1% | 2026-Q1 |
| Informed Momentum Co LLC trimmed | 56,494 | $3M | 0.1% | 2026-Q1 |
| Brevan Howard Capital Management LP trimmed | 53,882 | $3M | 0.1% | 2026-Q1 |
| Penserra Capital Management LLC added | 53,102 | $3M | 0.1% | 2026-Q1 |
| ExodusPoint Capital Management, LP added | 52,303 | $3M | 0.1% | 2026-Q1 |
| Fieldview Capital Management, LLC new | 51,072 | $2M | 0.1% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 50,299 | $2M | 0.1% | 2026-Q1 |
| OpenArc Corporate Advisory, LLC added | 48,353 | $2M | 0.1% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 44,525 | $2M | 0.1% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 44,320 | $2M | 0.1% | 2026-Q1 |
| Cerity Partners LLC added | 43,712 | $2M | 0.1% | 2026-Q1 |
| Schonfeld Strategic Advisors LLC trimmed | 43,599 | $2M | 0.1% | 2026-Q1 |
| Jain Global LLC added | 43,027 | $2M | 0.1% | 2026-Q1 |
| IEQ CAPITAL, LLC trimmed | 42,950 | $2M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 3,049,745 | $126M | 5.3% | 2025-Q4 stale |
| Fairmount Funds Management LLC trimmed | 1,319,688 | $54M | 2.3% | 2025-Q4 stale |
| Cubist Systematic Strategies, LLC trimmed | 381,319 | $15M | 0.6% | 2025-Q3 stale |
| Logos Global Management LP added | 350,000 | $14M | 0.6% | 2025-Q4 stale |
| JANE STREET GROUP, LLC trimmed | 242,430 | $10M | 0.4% | 2025-Q4 stale |
| Hillsdale Investment Management Inc. trimmed | 224,074 | $9M | 0.4% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 208,300 | $9M | 0.4% | 2025-Q4 stale |
| Walleye Capital LLC trimmed | 143,293 | $6M | 0.2% | 2025-Q4 stale |
| Kodai Capital Management LP new | 185,364 | $4M | 0.2% | 2025-Q1 stale |
| Atika Capital Management LLC new | 93,970 | $4M | 0.2% | 2025-Q4 stale |
| Vestal Point Capital, LP new | 169,864 | $4M | 0.2% | 2025-Q1 stale |
| GREAT LAKES ADVISORS, LLC new | 126,789 | $4M | 0.1% | 2025-Q2 stale |
| SILVERARC CAPITAL MANAGEMENT, LLC added | 88,910 | $3M | 0.1% | 2025-Q3 stale |
| WELLINGTON MANAGEMENT GROUP LLP added | 113,990 | $3M | 0.1% | 2025-Q2 stale |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC | 60,125 | $2M | 0.1% | 2025-Q4 stale |
| ADAGE CAPITAL PARTNERS GP, L.L.C. new | 59,000 | $2M | 0.1% | 2025-Q3 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.