Who owns RBRK (RBRK)
Which tracked institutional funds hold RBRK, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See RBRK 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
94 tracked funds added or opened RBRK while 217 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
RBRK’s largest tracked holder by dollar value, VANGUARD GROUP INC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 0.0pp gap the other way — the median holder sizes RBRK more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in RBRK 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 463 tracked filers holding RBRK, 297 increased or opened the position and 237 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 RBRK 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 47
- VANGUARD PORTFOLIO MANAGEMENT LLC$393M
- VANGUARD CAPITAL MANAGEMENT LLC$321M
- Champlain Investment Partners, LLC$62M
- Greenvale Capital LLP$50M
- VANGUARD FIDUCIARY TRUST CO$46M
- Capital World Investors$33M
Full exits 53
- VANGUARD GROUP INC$1.1B
- 1832 Asset Management L.P.$78M
- BIT Capital GmbH$70M
- VOLORIDGE INVESTMENT MANAGEMENT, LLC$39M
- LORD, ABBETT & CO. LLC$26M
- TEACHER RETIREMENT SYSTEM OF TEXAS$25M
Largest adds
- TWO SIGMA INVESTMENTS, LP$58M
- SG Americas Securities, LLC$51M
- UBS Group AG$47M
- Pictet Asset Management Holding SA$38M
- WELLS FARGO & COMPANY/MN$28M
- AQR CAPITAL MANAGEMENT LLC$22M
Largest trims
- BlackRock, Inc.$531M
- FIRST TRUST ADVISORS LP$301M
- NORGES BANK$157M
- FEDERATED HERMES, INC.$123M
- VOYA INVESTMENT MANAGEMENT LLC$110M
- MILLENNIUM MANAGEMENT LLC$73M
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 | 8,214,939 | $402M | 5.7% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 8,029,608 | $393M | 5.5% | 2026-Q1 |
| BlackRock, Inc. trimmed | 7,457,841 | $365M | 5.1% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 6,555,111 | $321M | 4.5% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 4,895,715 | $240M | 3.4% | 2026-Q1 |
| NORGES BANK trimmed | 3,091,593 | $189M | 2.6% | 2026-Q1 |
| VOYA INVESTMENT MANAGEMENT LLC trimmed | 3,736,521 | $183M | 2.6% | 2026-Q1 |
| PointState Capital LP added | 3,646,244 | $179M | 2.5% | 2026-Q1 |
| Pictet Asset Management Holding SA added | 3,325,503 | $163M | 2.3% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 2,702,893 | $132M | 1.9% | 2026-Q1 |
| STATE STREET CORP added | 2,566,813 | $126M | 1.8% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 2,313,244 | $113M | 1.6% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 2,213,261 | $105M | 1.5% | 2026-Q1 |
| UBS Group AG added | 1,955,045 | $96M | 1.3% | 2026-Q1 |
| Legal & General Group Plc trimmed | 1,823,377 | $89M | 1.3% | 2026-Q1 |
| MORGAN STANLEY added | 1,722,181 | $84M | 1.2% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 1,830,164 | $83M | 1.2% | 2026-Q1 |
| Penserra Capital Management LLC added | 1,538,782 | $75M | 1.1% | 2026-Q1 |
| Clearbridge Investments, LLC added | 1,448,294 | $71M | 1.0% | 2026-Q1 |
| INSTITUTIONAL VENTURE MANAGEMENT XV, LLC | 1,431,479 | $70M | 1.0% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. added | 872,613 | $67M | 0.9% | 2026-Q1 |
| FEDERATED HERMES, INC. trimmed | 1,317,727 | $65M | 0.9% | 2026-Q1 |
| Champlain Investment Partners, LLC added | 1,259,925 | $62M | 0.9% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 1,232,277 | $60M | 0.8% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN added | 1,180,946 | $58M | 0.8% | 2026-Q1 |
| SG Americas Securities, LLC added | 1,171,286 | $57M | 0.8% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 1,156,283 | $57M | 0.8% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 1,021,621 | $50M | 0.7% | 2026-Q1 |
| Greenvale Capital LLP new | 1,020,000 | $50M | 0.7% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 949,362 | $46M | 0.7% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 905,745 | $44M | 0.6% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 887,640 | $43M | 0.6% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 854,514 | $42M | 0.6% | 2026-Q1 |
| Squarepoint Ops LLC trimmed | 817,005 | $40M | 0.6% | 2026-Q1 |
| Fiera Capital Corp added | 797,830 | $39M | 0.5% | 2026-Q1 |
| NORTHERN TRUST CORP added | 755,152 | $37M | 0.5% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 733,411 | $36M | 0.5% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 731,217 | $36M | 0.5% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 728,595 | $36M | 0.5% | 2026-Q1 |
| BANK OF NOVA SCOTIA trimmed | 726,670 | $36M | 0.5% | 2026-Q1 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 723,370 | $35M | 0.5% | 2026-Q1 |
| Stephens Investment Management Group LLC added | 699,389 | $34M | 0.5% | 2026-Q1 |
| IEQ CAPITAL, LLC trimmed | 689,846 | $34M | 0.5% | 2026-Q1 |
| Capital World Investors new | 663,678 | $33M | 0.5% | 2026-Q1 |
| BAIN CAPITAL VENTURE INVESTORS, LLC | 659,640 | $32M | 0.5% | 2026-Q1 |
| Capital International Investors trimmed | 618,119 | $30M | 0.4% | 2026-Q1 |
| Atreides Management, LP trimmed | 566,454 | $28M | 0.4% | 2026-Q1 |
| Amundi added | 561,496 | $27M | 0.4% | 2026-Q1 |
| Bank of New York Mellon Corp added | 557,501 | $27M | 0.4% | 2026-Q1 |
| Holocene Advisors, LP added | 555,713 | $27M | 0.4% | 2026-Q1 |
| CONGRESS ASSET MANAGEMENT CO new | 545,725 | $27M | 0.4% | 2026-Q1 |
| ALKEON CAPITAL MANAGEMENT LLC trimmed | 500,000 | $24M | 0.3% | 2026-Q1 |
| Bienville Capital Management, LLC added | 471,691 | $23M | 0.3% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP added | 470,487 | $23M | 0.3% | 2026-Q1 |
| BARCLAYS PLC added | 457,587 | $22M | 0.3% | 2026-Q1 |
| Trexquant Investment LP added | 443,696 | $22M | 0.3% | 2026-Q1 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. added | 412,159 | $20M | 0.3% | 2026-Q1 |
| CI INVESTMENTS INC. added | 404,637 | $20M | 0.3% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 399,690 | $20M | 0.3% | 2026-Q1 |
| ARK Investment Management LLC trimmed | 395,049 | $19M | 0.3% | 2026-Q1 |
| Beacon Pointe Advisors, LLC added | 392,054 | $19M | 0.3% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 377,489 | $18M | 0.3% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 375,259 | $18M | 0.3% | 2026-Q1 |
| Nuveen, LLC trimmed | 372,241 | $18M | 0.3% | 2026-Q1 |
| Abu Dhabi Investment Council Co P.J.S.C new | 368,256 | $18M | 0.3% | 2026-Q1 |
| MARSHALL WACE, LLP trimmed | 363,031 | $18M | 0.2% | 2026-Q1 |
| CITIGROUP INC added | 344,121 | $17M | 0.2% | 2026-Q1 |
| ING GROEP NV added | 334,100 | $16M | 0.2% | 2026-Q1 |
| Voleon Capital Management LP trimmed | 330,959 | $16M | 0.2% | 2026-Q1 |
| Sumitomo Mitsui Trust Group, Inc. trimmed | 311,213 | $15M | 0.2% | 2026-Q1 |
| Amova Asset Management Americas, Inc. trimmed | 311,213 | $15M | 0.2% | 2026-Q1 |
| Junto Capital Management LP new | 294,470 | $14M | 0.2% | 2026-Q1 |
| Swiss National Bank added | 292,100 | $14M | 0.2% | 2026-Q1 |
| FIL Ltd added | 280,854 | $14M | 0.2% | 2026-Q1 |
| BAMCO INC /NY/ added | 277,535 | $14M | 0.2% | 2026-Q1 |
| VANGUARD GROUP INC added | 14,483,198 | $1.1B | 15.6% | 2025-Q4 stale |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 955,600 | $86M | 1.2% | 2025-Q2 stale |
| 1832 Asset Management L.P. added | 1,022,300 | $78M | 1.1% | 2025-Q4 stale |
| BIT Capital GmbH added | 910,382 | $70M | 1.0% | 2025-Q4 stale |
| PATHWAY CAPITAL MANAGEMENT, LP trimmed | 643,199 | $58M | 0.8% | 2025-Q2 stale |
| Altimeter Capital Management, LP trimmed | 832,003 | $51M | 0.7% | 2025-Q1 stale |
| Evergreen Quality Fund GP, Ltd. new | 592,300 | $49M | 0.7% | 2025-Q3 stale |
| MACQUARIE GROUP LTD added | 551,964 | $45M | 0.6% | 2025-Q3 stale |
| Driehaus Capital Management LLC added | 510,935 | $42M | 0.6% | 2025-Q3 stale |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC added | 510,882 | $39M | 0.5% | 2025-Q4 stale |
| LORD, ABBETT & CO. LLC trimmed | 340,614 | $26M | 0.4% | 2025-Q4 stale |
| TEACHER RETIREMENT SYSTEM OF TEXAS added | 326,438 | $25M | 0.4% | 2025-Q4 stale |
| Perpetual Ltd trimmed | 320,680 | $25M | 0.3% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 289,500 | $22M | 0.3% | 2025-Q4 stale |
| TUDOR INVESTMENT CORP ET AL trimmed | 230,719 | $21M | 0.3% | 2025-Q2 stale |
| LMR Partners LLP added | 240,250 | $20M | 0.3% | 2025-Q3 stale |
| Alta Park Capital, LP trimmed | 247,762 | $19M | 0.3% | 2025-Q4 stale |
| Monolith Management Ltd new | 211,050 | $19M | 0.3% | 2025-Q2 stale |
| BALYASNY ASSET MANAGEMENT L.P. added | 225,549 | $19M | 0.3% | 2025-Q3 stale |
| GILDER GAGNON HOWE & CO LLC trimmed | 192,223 | $16M | 0.2% | 2025-Q3 stale |
| Science & Technology Partners, L.P. new | 171,140 | $15M | 0.2% | 2025-Q2 stale |
| Legacy Capital Group California, Inc. trimmed | 181,095 | $14M | 0.2% | 2025-Q4 stale |
| Quadrature Capital Ltd added | 150,843 | $14M | 0.2% | 2025-Q2 stale |
| SUSQUEHANNA ADVISORS GROUP, INC. new | 150,413 | $13M | 0.2% | 2025-Q2 stale |
| State of Tennessee, Department of Treasury added | 137,979 | $12M | 0.2% | 2025-Q2 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.