Who owns ROCK (ROCK)
Which tracked institutional funds hold ROCK, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ROCK 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
32 tracked funds added or opened ROCK while 83 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
ROCK’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 conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ROCK 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 227 tracked filers holding ROCK, 130 increased or opened the position and 133 reduced or closed it; over the same quarter, open-market insider Form 4s were net purchases.
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 ROCK 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 16
- VANGUARD PORTFOLIO MANAGEMENT LLC$53M
- VANGUARD CAPITAL MANAGEMENT LLC$53M
- SG Capital Management LLC$9M
- VANGUARD FIDUCIARY TRUST CO$8M
- Invenomic Capital Management LP$7M
- CastleKnight Management LP$6M
Full exits 18
- VANGUARD GROUP INC$130M
- Swedbank AB$13M
- Ancora Advisors LLC$6M
- Point72 Asset Management, L.P.$6M
- JANE STREET GROUP, LLC$5M
- Robeco Schweiz AG$4M
Largest adds
- ALLIANCEBERNSTEIN L.P.$24M
- FIRST WILSHIRE SECURITIES MANAGEMENT INC$14M
- MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd.$5M
- UBS Group AG$5M
- BALYASNY ASSET MANAGEMENT L.P.$3M
- AQR CAPITAL MANAGEMENT LLC$2M
Largest trims
- BlackRock, Inc.$112M
- VICTORY CAPITAL MANAGEMENT INC$34M
- Boston Partners$19M
- DIMENSIONAL FUND ADVISORS LP$16M
- STATE STREET CORP$14M
- FMR LLC$12M
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 | 4,282,140 | $171M | 12.4% | 2026-Q1 |
| BlackRock, Inc. trimmed | 3,352,353 | $134M | 9.7% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. added | 2,198,453 | $109M | 7.9% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 1,705,997 | $68M | 4.9% | 2026-Q1 |
| STATE STREET CORP trimmed | 1,345,665 | $54M | 3.9% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 1,323,731 | $53M | 3.8% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 1,322,342 | $53M | 3.8% | 2026-Q1 |
| BARROW HANLEY MEWHINNEY & STRAUSS LLC added | 1,169,975 | $47M | 3.4% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 777,629 | $31M | 2.3% | 2026-Q1 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 742,267 | $30M | 2.1% | 2026-Q1 |
| FRONTIER CAPITAL MANAGEMENT CO LLC added | 688,272 | $27M | 2.0% | 2026-Q1 |
| Boston Partners trimmed | 686,625 | $27M | 2.0% | 2026-Q1 |
| FIRST WILSHIRE SECURITIES MANAGEMENT INC added | 499,923 | $20M | 1.4% | 2026-Q1 |
| T. Rowe Price Investment Management, Inc. added | 467,049 | $19M | 1.4% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 440,483 | $18M | 1.3% | 2026-Q1 |
| SEGALL BRYANT & HAMILL, LLC added | 430,995 | $17M | 1.2% | 2026-Q1 |
| MORGAN STANLEY trimmed | 362,284 | $14M | 1.0% | 2026-Q1 |
| PALISADE CAPITAL MANAGEMENT, LP trimmed | 358,875 | $14M | 1.0% | 2026-Q1 |
| NORTHERN TRUST CORP added | 333,896 | $13M | 1.0% | 2026-Q1 |
| ROYCE & ASSOCIATES LP added | 288,541 | $12M | 0.8% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 249,672 | $10M | 0.7% | 2026-Q1 |
| KENNEDY CAPITAL MANAGEMENT LLC trimmed | 247,097 | $10M | 0.7% | 2026-Q1 |
| SG Capital Management LLC trimmed | 233,808 | $9M | 0.7% | 2026-Q1 |
| UBS Group AG added | 197,333 | $8M | 0.6% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 194,713 | $8M | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 193,746 | $8M | 0.6% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC added | 186,012 | $7M | 0.5% | 2026-Q1 |
| Invenomic Capital Management LP added | 183,072 | $7M | 0.5% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 164,303 | $7M | 0.5% | 2026-Q1 |
| Invesco Ltd. added | 158,329 | $6M | 0.5% | 2026-Q1 |
| CastleKnight Management LP new | 150,500 | $6M | 0.4% | 2026-Q1 |
| NEW YORK STATE COMMON RETIREMENT FUND trimmed | 144,225 | $6M | 0.4% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 139,274 | $6M | 0.4% | 2026-Q1 |
| RBF Capital, LLC | 123,099 | $5M | 0.4% | 2026-Q1 |
| SYSTEMATIC FINANCIAL MANAGEMENT LP trimmed | 118,468 | $5M | 0.3% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 118,449 | $5M | 0.3% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. added | 116,776 | $5M | 0.3% | 2026-Q1 |
| NORDEA INVESTMENT MANAGEMENT AB trimmed | 117,469 | $5M | 0.3% | 2026-Q1 |
| Pacer Advisors, Inc. added | 116,827 | $5M | 0.3% | 2026-Q1 |
| GAMCO INVESTORS, INC. ET AL added | 105,795 | $4M | 0.3% | 2026-Q1 |
| Public Sector Pension Investment Board added | 105,735 | $4M | 0.3% | 2026-Q1 |
| Congruence Capital, LLC new | 105,371 | $4M | 0.3% | 2026-Q1 |
| PRIMECAP MANAGEMENT CO/CA/ | 95,600 | $4M | 0.3% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 94,571 | $4M | 0.3% | 2026-Q1 |
| RHUMBLINE ADVISERS added | 89,165 | $4M | 0.3% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC added | 81,312 | $3M | 0.2% | 2026-Q1 |
| Nuveen, LLC added | 72,781 | $3M | 0.2% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 66,105 | $3M | 0.2% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 64,347 | $3M | 0.2% | 2026-Q1 |
| BESSEMER GROUP INC added | 64,048 | $3M | 0.2% | 2026-Q1 |
| Legal & General Group Plc trimmed | 63,914 | $3M | 0.2% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 63,817 | $3M | 0.2% | 2026-Q1 |
| Expect Equity LLC added | 63,467 | $3M | 0.2% | 2026-Q1 |
| Edgestream Partners, L.P. added | 61,019 | $2M | 0.2% | 2026-Q1 |
| Swiss National Bank | 58,200 | $2M | 0.2% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 57,919 | $2M | 0.2% | 2026-Q1 |
| Teton Advisors, LLC | 52,000 | $2M | 0.2% | 2026-Q1 |
| South Dakota Investment Council | 51,790 | $2M | 0.1% | 2026-Q1 |
| Assenagon Asset Management S.A. added | 49,659 | $2M | 0.1% | 2026-Q1 |
| BARCLAYS PLC trimmed | 43,870 | $2M | 0.1% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 42,539 | $2M | 0.1% | 2026-Q1 |
| Kennondale Capital Management LLC | 41,852 | $2M | 0.1% | 2026-Q1 |
| Quantinno Capital Management LP added | 38,692 | $2M | 0.1% | 2026-Q1 |
| Advisors Preferred, LLC new | 38,110 | $2M | 0.1% | 2026-Q1 |
| SEI INVESTMENTS CO trimmed | 36,750 | $1M | 0.1% | 2026-Q1 |
| PRUDENTIAL FINANCIAL INC added | 36,530 | $1M | 0.1% | 2026-Q1 |
| WEDGE CAPITAL MANAGEMENT L L P/NC added | 35,862 | $1M | 0.1% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 35,501 | $1M | 0.1% | 2026-Q1 |
| Brooklyn Investment Group added | 35,445 | $1M | 0.1% | 2026-Q1 |
| CITIGROUP INC added | 34,590 | $1M | 0.1% | 2026-Q1 |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM trimmed | 34,526 | $1M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 2,631,812 | $130M | 9.4% | 2025-Q4 stale |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 416,963 | $26M | 1.9% | 2025-Q3 stale |
| Swedbank AB | 267,101 | $13M | 1.0% | 2025-Q4 stale |
| Ancora Advisors LLC trimmed | 119,858 | $6M | 0.4% | 2025-Q4 stale |
| Point72 Asset Management, L.P. added | 118,195 | $6M | 0.4% | 2025-Q4 stale |
| CSM Advisors, LLC new | 80,094 | $5M | 0.4% | 2025-Q3 stale |
| JANE STREET GROUP, LLC added | 95,065 | $5M | 0.3% | 2025-Q4 stale |
| Robeco Schweiz AG trimmed | 90,000 | $4M | 0.3% | 2025-Q4 stale |
| VAN ECK ASSOCIATES CORP added | 67,715 | $4M | 0.3% | 2025-Q3 stale |
| Cubist Systematic Strategies, LLC trimmed | 67,525 | $4M | 0.3% | 2025-Q2 stale |
| WINTON GROUP Ltd added | 57,538 | $3M | 0.2% | 2025-Q2 stale |
| Teton Advisors, Inc. trimmed | 56,000 | $3M | 0.2% | 2025-Q2 stale |
| NORGES BANK trimmed | 46,718 | $3M | 0.2% | 2025-Q3 stale |
| Qube Research & Technologies Ltd trimmed | 56,583 | $3M | 0.2% | 2025-Q4 stale |
| Phocas Financial Corp. trimmed | 55,950 | $3M | 0.2% | 2025-Q4 stale |
| Empowered Funds, LLC new | 42,606 | $3M | 0.2% | 2025-Q2 stale |
| Clayton Partners LLC trimmed | 49,652 | $2M | 0.2% | 2025-Q4 stale |
| MILLENNIUM MANAGEMENT LLC added | 49,445 | $2M | 0.2% | 2025-Q4 stale |
| SEIZERT CAPITAL PARTNERS, LLC trimmed | 38,686 | $2M | 0.2% | 2025-Q3 stale |
| State of New Jersey Common Pension Fund D added | 34,779 | $2M | 0.2% | 2025-Q3 stale |
| CLARK ESTATES INC/NY new | 35,000 | $2M | 0.1% | 2025-Q2 stale |
| ExodusPoint Capital Management, LP added | 37,801 | $2M | 0.1% | 2025-Q4 stale |
| Trexquant Investment LP trimmed | 27,994 | $2M | 0.1% | 2025-Q3 stale |
| Covalent Partners LLC new | 27,000 | $2M | 0.1% | 2025-Q3 stale |
| ANCHOR CAPITAL ADVISORS LLC added | 26,733 | $2M | 0.1% | 2025-Q3 stale |
| Nebula Research & Development LLC added | 27,511 | $2M | 0.1% | 2025-Q2 stale |
| Allspring Global Investments Holdings, LLC trimmed | 32,221 | $2M | 0.1% | 2025-Q4 stale |
| Jackson Creek Investment Advisors LLC added | 27,180 | $2M | 0.1% | 2025-Q2 stale |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND added | 22,900 | $1M | 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.