Who owns Accelerant Holdings (ARX)
Which tracked institutional funds hold ARX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ARX company fundamentals →
Ownership as of the 2026-Q1 13F filings. 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
36 tracked funds added or opened ARX while 35 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
ARX’s largest tracked holder by dollar value, SECURITY BENEFIT LIFE INSURANCE CO /KS/, sizes it at 41.2% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 41.2pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ARX 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 107 tracked filers holding ARX, 70 increased or opened the position and 48 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 ARX 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 17
- VANGUARD PORTFOLIO MANAGEMENT LLC$28M
- VANGUARD CAPITAL MANAGEMENT LLC$26M
- Cresset Asset Management, LLC$25M
- Qube Research & Technologies Ltd$12M
- JANE STREET GROUP, LLC$11M
- SUSQUEHANNA INTERNATIONAL GROUP, LLP$9M
Full exits 15
- Balyasny Asset Management L.P.$45M
- VANGUARD GROUP INC$36M
- Deer Park Road Corp$33M
- NORGES BANK$11M
- FRED ALGER MANAGEMENT, LLC$7M
- TEACHER RETIREMENT SYSTEM OF TEXAS$3M
Largest adds
- MARSHALL WACE, LLP$25M
- AMERICAN CENTURY COMPANIES INC$18M
- T. Rowe Price Investment Management, Inc.$7M
- BARINGS LLC$4M
- CITADEL ADVISORS LLC$4M
- BNP PARIBAS FINANCIAL MARKETS$3M
Largest trims
- Grandeur Peak Global Advisors, LLC$26M
- Capital World Investors$25M
- SECURITY BENEFIT LIFE INSURANCE CO /KS/$18M
- Azora Capital LP$13M
- GILDER GAGNON HOWE & CO LLC$11M
- ArrowMark Colorado Holdings 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 |
|---|---|---|---|---|
| SECURITY BENEFIT LIFE INSURANCE CO /KS/ | 5,866,257 | $78M | 8.2% | 2026-Q1 |
| Capital World Investors trimmed | 5,152,741 | $69M | 7.2% | 2026-Q1 |
| Keenan Capital, LLC added | 3,992,923 | $53M | 5.6% | 2026-Q1 |
| GILDER GAGNON HOWE & CO LLC added | 3,743,364 | $50M | 5.3% | 2026-Q1 |
| BARINGS LLC | 3,128,867 | $46M | 4.8% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. trimmed | 2,800,188 | $46M | 4.8% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 3,188,505 | $43M | 4.5% | 2026-Q1 |
| MARSHALL WACE, LLP added | 2,274,152 | $30M | 3.2% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 2,113,565 | $28M | 3.0% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 2,020,368 | $27M | 2.8% | 2026-Q1 |
| Azora Capital LP trimmed | 1,980,211 | $26M | 2.8% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 1,938,938 | $26M | 2.7% | 2026-Q1 |
| Cresset Asset Management, LLC new | 1,839,620 | $25M | 2.6% | 2026-Q1 |
| FMR LLC added | 1,806,280 | $24M | 2.5% | 2026-Q1 |
| ArrowMark Colorado Holdings LLC trimmed | 1,548,224 | $21M | 2.2% | 2026-Q1 |
| BAMCO INC /NY/ trimmed | 1,208,794 | $16M | 1.7% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 1,144,206 | $15M | 1.6% | 2026-Q1 |
| T. Rowe Price Investment Management, Inc. added | 975,936 | $13M | 1.4% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 930,942 | $12M | 1.3% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 860,697 | $11M | 1.2% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP new | 708,046 | $9M | 1.0% | 2026-Q1 |
| UBS Group AG added | 685,647 | $9M | 1.0% | 2026-Q1 |
| G2 Investment Partners Management LLC added | 372,811 | $5M | 0.5% | 2026-Q1 |
| Woodline Partners LP added | 367,157 | $5M | 0.5% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 305,244 | $4M | 0.4% | 2026-Q1 |
| MORGAN STANLEY added | 287,175 | $4M | 0.4% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 276,600 | $4M | 0.4% | 2026-Q1 |
| XTX Topco Ltd added | 237,669 | $3M | 0.3% | 2026-Q1 |
| Squarepoint Ops LLC added | 212,791 | $3M | 0.3% | 2026-Q1 |
| Owls Nest Partners IA, LLC new | 209,707 | $3M | 0.3% | 2026-Q1 |
| SEVEN GRAND MANAGERS, LLC | 200,000 | $3M | 0.3% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 180,186 | $2M | 0.3% | 2026-Q1 |
| Point72 Asset Management, L.P. added | 166,692 | $2M | 0.2% | 2026-Q1 |
| BlackRock, Inc. trimmed | 165,564 | $2M | 0.2% | 2026-Q1 |
| CANNELL CAPITAL LLC new | 156,149 | $2M | 0.2% | 2026-Q1 |
| Militia Capital Management LLC new | 150,000 | $2M | 0.2% | 2026-Q1 |
| Trexquant Investment LP new | 149,119 | $2M | 0.2% | 2026-Q1 |
| Robertson Opportunity Capital, LLC new | 135,012 | $2M | 0.2% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 125,068 | $2M | 0.2% | 2026-Q1 |
| Schonfeld Strategic Advisors LLC added | 113,795 | $2M | 0.2% | 2026-Q1 |
| Burkehill Global Management, LP | 100,000 | $1M | 0.1% | 2026-Q1 |
| Jain Global LLC added | 86,418 | $1M | 0.1% | 2026-Q1 |
| Lighthouse Investment Partners, LLC trimmed | 85,406 | $1M | 0.1% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 82,680 | $1M | 0.1% | 2026-Q1 |
| BOOTHBAY FUND MANAGEMENT, LLC added | 78,677 | $1M | 0.1% | 2026-Q1 |
| Swiss National Bank | 77,900 | $1M | 0.1% | 2026-Q1 |
| TIGER GLOBAL MANAGEMENT LLC | 75,000 | $1M | 0.1% | 2026-Q1 |
| SEI INVESTMENTS CO added | 73,935 | $988K | 0.1% | 2026-Q1 |
| SummitTX Capital, L.P. added | 62,999 | $842K | 0.1% | 2026-Q1 |
| Hudson Bay Capital Management LP added | 55,276 | $738K | 0.1% | 2026-Q1 |
| Brevan Howard Capital Management LP new | 54,416 | $727K | 0.1% | 2026-Q1 |
| STATE OF WISCONSIN INVESTMENT BOARD added | 53,463 | $714K | 0.1% | 2026-Q1 |
| Interval Partners, LP trimmed | 49,534 | $662K | 0.1% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 47,960 | $641K | 0.1% | 2026-Q1 |
| BARCLAYS PLC added | 46,693 | $624K | 0.1% | 2026-Q1 |
| Engineers Gate Manager LP new | 44,016 | $588K | 0.1% | 2026-Q1 |
| Jump Financial, LLC new | 44,005 | $588K | 0.1% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 41,669 | $557K | 0.1% | 2026-Q1 |
| Grandeur Peak Global Advisors, LLC trimmed | 39,573 | $529K | 0.1% | 2026-Q1 |
| Jefferies Financial Group Inc. trimmed | 39,178 | $523K | 0.1% | 2026-Q1 |
| Aquatic Capital Management LLC new | 37,435 | $500K | 0.1% | 2026-Q1 |
| STATE STREET CORP added | 37,306 | $498K | 0.1% | 2026-Q1 |
| Bank of New York Mellon Corp new | 36,556 | $488K | 0.1% | 2026-Q1 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | 34,972 | $467K | 0.0% | 2026-Q1 |
| Catalyst Funds Management Pty Ltd new | 34,900 | $466K | 0.0% | 2026-Q1 |
| Zurcher Kantonalbank (Zurich Cantonalbank) | 32,300 | $432K | 0.0% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN new | 28,850 | $385K | 0.0% | 2026-Q1 |
| Balyasny Asset Management L.P. added | 2,733,595 | $45M | 4.7% | 2025-Q4 stale |
| VANGUARD GROUP INC trimmed | 2,173,243 | $36M | 3.7% | 2025-Q4 stale |
| Deer Park Road Corp new | 2,099,057 | $33M | 3.4% | 2025-Q4 stale |
| Driehaus Capital Management LLC new | 1,011,940 | $15M | 1.6% | 2025-Q3 stale |
| NORGES BANK new | 665,076 | $11M | 1.1% | 2025-Q4 stale |
| Journey Advisory Group, LLC new | 432,526 | $8M | 0.8% | 2025-Q3 stale |
| FRED ALGER MANAGEMENT, LLC trimmed | 439,698 | $7M | 0.8% | 2025-Q4 stale |
| CenterBook Partners LP new | 382,645 | $6M | 0.6% | 2025-Q3 stale |
| Dragoneer Investment Group, LLC new | 336,361 | $5M | 0.5% | 2025-Q3 stale |
| Verition Fund Management LLC new | 272,240 | $4M | 0.4% | 2025-Q3 stale |
| SOROS FUND MANAGEMENT LLC new | 225,000 | $3M | 0.4% | 2025-Q3 stale |
| TEACHER RETIREMENT SYSTEM OF TEXAS added | 176,043 | $3M | 0.3% | 2025-Q4 stale |
| Counterpoint Mutual Funds LLC new | 175,967 | $3M | 0.3% | 2025-Q4 stale |
| Lykos Global Management, LP new | 175,000 | $3M | 0.3% | 2025-Q4 stale |
| NEUBERGER BERMAN GROUP LLC trimmed | 160,047 | $3M | 0.3% | 2025-Q4 stale |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 150,000 | $2M | 0.3% | 2025-Q4 stale |
| Walleye Capital LLC trimmed | 125,880 | $2M | 0.2% | 2025-Q4 stale |
| Ghisallo Capital Management LLC trimmed | 100,000 | $2M | 0.2% | 2025-Q4 stale |
| Pembroke Management, LTD new | 93,785 | $1M | 0.1% | 2025-Q3 stale |
| TUDOR INVESTMENT CORP ET AL | 72,173 | $1M | 0.1% | 2025-Q4 stale |
| Allianz Asset Management GmbH new | 71,399 | $1M | 0.1% | 2025-Q3 stale |
| Cubist Systematic Strategies, LLC new | 66,391 | $989K | 0.1% | 2025-Q3 stale |
| Yorktown Management & Research Co Inc new | 59,300 | $970K | 0.1% | 2025-Q4 stale |
| PICTON MAHONEY ASSET MANAGEMENT new | 52,349 | $780K | 0.1% | 2025-Q3 stale |
| Limestone Investment Advisors LP new | 40,900 | $609K | 0.1% | 2025-Q3 stale |
| TD Asset Management Inc new | 40,072 | $597K | 0.1% | 2025-Q3 stale |
| D. E. Shaw & Co., Inc. trimmed | 34,694 | $567K | 0.1% | 2025-Q4 stale |
| FRANKLIN RESOURCES INC new | 35,908 | $535K | 0.1% | 2025-Q3 stale |
| 3G Capital Partners LP new | 35,000 | $521K | 0.1% | 2025-Q3 stale |
| Corient Private Wealth LLC new | 30,000 | $447K | 0.0% | 2025-Q3 stale |
| PharVision Advisers, LLC added | 23,839 | $390K | 0.0% | 2025-Q4 stale |
| Oribel Capital Management, LP new | 25,900 | $386K | 0.0% | 2025-Q3 stale |
| GSA CAPITAL PARTNERS LLP new | 23,518 | $385K | 0.0% | 2025-Q4 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.