Who owns Iridium Communications Inc. (IRDM)
Which tracked institutional funds hold IRDM, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See IRDM 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
The tracked-fund tape on IRDM is one-sided between 2025-Q4 and 2026-Q1: 150 added or opened and 47 trimmed or exited — on balance accumulating.
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
IRDM’s largest tracked holder by dollar value, BlackRock, Inc., 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 IRDM more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in IRDM 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 379 tracked filers holding IRDM, 227 increased or opened the position and 156 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
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 IRDM 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 40
- VANGUARD PORTFOLIO MANAGEMENT LLC$169M
- VANGUARD CAPITAL MANAGEMENT LLC$114M
- NORGES BANK$25M
- VANGUARD FIDUCIARY TRUST CO$18M
- PANAGORA ASSET MANAGEMENT INC$15M
- Robertson Opportunity Capital, LLC$8M
Full exits 21
- VANGUARD GROUP INC$163M
- VOLORIDGE INVESTMENT MANAGEMENT, LLC$14M
- Trexquant Investment LP$9M
- Qube Research & Technologies Ltd$9M
- Maxi Investments CY Ltd$7M
- TWO SIGMA ADVISERS, LP$6M
Largest adds
- AQR CAPITAL MANAGEMENT LLC$72M
- STATE STREET CORP$57M
- Gotham Asset Management, LLC$53M
- Silver Heights Capital Management Inc$51M
- AMERICAN CENTURY COMPANIES INC$43M
- BlackRock, Inc.$27M
Largest trims
- CITADEL ADVISORS LLC$18M
- GOLDMAN SACHS GROUP INC$15M
- TUDOR INVESTMENT CORP ET AL$11M
- CAPITAL FUND MANAGEMENT S.A.$5M
- Bridgewater Associates, LP$4M
- MILLENNIUM MANAGEMENT LLC$4M
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 |
|---|---|---|---|---|
| BlackRock, Inc. trimmed | 9,667,064 | $268M | 9.9% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 6,091,749 | $169M | 6.2% | 2026-Q1 |
| Silver Heights Capital Management Inc trimmed | 5,145,479 | $143M | 5.3% | 2026-Q1 |
| STATE STREET CORP added | 5,050,166 | $140M | 5.2% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 4,111,325 | $114M | 4.2% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 3,469,954 | $96M | 3.6% | 2026-Q1 |
| Gotham Asset Management, LLC added | 3,353,971 | $93M | 3.4% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 2,900,060 | $80M | 3.0% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 2,159,061 | $60M | 2.2% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 2,007,011 | $56M | 2.1% | 2026-Q1 |
| Man Group plc added | 1,907,044 | $53M | 2.0% | 2026-Q1 |
| ARK Investment Management LLC trimmed | 1,726,802 | $48M | 1.8% | 2026-Q1 |
| MORGAN STANLEY trimmed | 1,583,337 | $44M | 1.6% | 2026-Q1 |
| Pacer Advisors, Inc. trimmed | 1,138,681 | $43M | 1.6% | 2026-Q1 |
| VAN ECK ASSOCIATES CORP added | 1,504,628 | $42M | 1.5% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 1,366,005 | $38M | 1.4% | 2026-Q1 |
| UBS Group AG added | 1,284,561 | $36M | 1.3% | 2026-Q1 |
| SCHRODER INVESTMENT MANAGEMENT GROUP added | 1,282,639 | $34M | 1.3% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 1,150,450 | $32M | 1.2% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 1,101,231 | $31M | 1.1% | 2026-Q1 |
| BARCLAYS PLC added | 994,069 | $28M | 1.0% | 2026-Q1 |
| Select Equity Group, L.P. added | 942,519 | $26M | 1.0% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 928,388 | $26M | 1.0% | 2026-Q1 |
| JUPITER ASSET MANAGEMENT LTD added | 893,282 | $25M | 0.9% | 2026-Q1 |
| Invesco Ltd. trimmed | 890,189 | $25M | 0.9% | 2026-Q1 |
| NORGES BANK trimmed | 900,509 | $25M | 0.9% | 2026-Q1 |
| NORTHERN TRUST CORP trimmed | 863,494 | $24M | 0.9% | 2026-Q1 |
| Sumitomo Mitsui Trust Group, Inc. trimmed | 791,773 | $22M | 0.8% | 2026-Q1 |
| Penserra Capital Management LLC trimmed | 755,728 | $21M | 0.8% | 2026-Q1 |
| Amova Asset Management Americas, Inc. trimmed | 736,973 | $20M | 0.8% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 708,297 | $19M | 0.7% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 636,855 | $18M | 0.7% | 2026-Q1 |
| PINNACLE ASSOCIATES LTD trimmed | 562,741 | $16M | 0.6% | 2026-Q1 |
| Mitsubishi UFJ Asset Management Co., Ltd. added | 538,427 | $15M | 0.6% | 2026-Q1 |
| FMR LLC added | 536,536 | $15M | 0.5% | 2026-Q1 |
| PANAGORA ASSET MANAGEMENT INC added | 529,520 | $15M | 0.5% | 2026-Q1 |
| BROWN ADVISORY INC added | 512,576 | $14M | 0.5% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC added | 508,290 | $14M | 0.5% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 494,662 | $14M | 0.5% | 2026-Q1 |
| Nuveen, LLC trimmed | 425,145 | $12M | 0.4% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP trimmed | 402,428 | $11M | 0.4% | 2026-Q1 |
| STIFEL FINANCIAL CORP added | 397,887 | $11M | 0.4% | 2026-Q1 |
| Legal & General Group Plc trimmed | 378,692 | $11M | 0.4% | 2026-Q1 |
| Public Sector Pension Investment Board added | 375,511 | $10M | 0.4% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC added | 368,276 | $10M | 0.4% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 359,530 | $10M | 0.4% | 2026-Q1 |
| Russell Investments Group, Ltd. added | 352,947 | $10M | 0.4% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 352,249 | $10M | 0.4% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 351,234 | $10M | 0.4% | 2026-Q1 |
| JANUS HENDERSON GROUP PLC added | 306,684 | $9M | 0.3% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 291,694 | $8M | 0.3% | 2026-Q1 |
| Robertson Opportunity Capital, LLC | 287,346 | $8M | 0.3% | 2026-Q1 |
| CX Institutional new | 272,787 | $8M | 0.3% | 2026-Q1 |
| Defiance ETFs, LLC trimmed | 255,175 | $7M | 0.3% | 2026-Q1 |
| NORDEA INVESTMENT MANAGEMENT AB trimmed | 255,788 | $7M | 0.3% | 2026-Q1 |
| RHUMBLINE ADVISERS added | 234,248 | $6M | 0.2% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC added | 233,301 | $6M | 0.2% | 2026-Q1 |
| BLAIR WILLIAM & CO/IL trimmed | 220,251 | $6M | 0.2% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 219,206 | $6M | 0.2% | 2026-Q1 |
| BESSEMER GROUP INC added | 217,485 | $6M | 0.2% | 2026-Q1 |
| ArchPoint Investors | 197,066 | $5M | 0.2% | 2026-Q1 |
| LOS ANGELES CAPITAL MANAGEMENT LLC added | 192,128 | $5M | 0.2% | 2026-Q1 |
| Swiss National Bank trimmed | 186,400 | $5M | 0.2% | 2026-Q1 |
| COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS trimmed | 161,046 | $4M | 0.2% | 2026-Q1 |
| MORGENS WATERFALL VINTIADIS & CO INC new | 154,000 | $4M | 0.2% | 2026-Q1 |
| Retirement Systems of Alabama | 151,400 | $4M | 0.2% | 2026-Q1 |
| Holocene Advisors, LP added | 149,354 | $4M | 0.2% | 2026-Q1 |
| PDT Partners, LLC | 138,207 | $4M | 0.1% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 128,100 | $4M | 0.1% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 123,555 | $3M | 0.1% | 2026-Q1 |
| Daiwa Securities Group Inc. added | 120,500 | $3M | 0.1% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 119,989 | $3M | 0.1% | 2026-Q1 |
| Mariner, LLC added | 117,695 | $3M | 0.1% | 2026-Q1 |
| ALGERT GLOBAL LLC trimmed | 115,088 | $3M | 0.1% | 2026-Q1 |
| CITIGROUP INC added | 114,021 | $3M | 0.1% | 2026-Q1 |
| Oak Thistle LLC added | 113,057 | $3M | 0.1% | 2026-Q1 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 112,063 | $3M | 0.1% | 2026-Q1 |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM trimmed | 111,212 | $3M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 9,351,124 | $163M | 6.0% | 2025-Q4 stale |
| Van Berkom & Associates Inc. trimmed | 2,863,178 | $86M | 3.2% | 2025-Q2 stale |
| Synergy Asset Management, LLC added | 1,324,366 | $40M | 1.5% | 2025-Q3 stale |
| ArrowMark Colorado Holdings LLC trimmed | 1,296,544 | $39M | 1.4% | 2025-Q2 stale |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC added | 812,037 | $14M | 0.5% | 2025-Q4 stale |
| Cubist Systematic Strategies, LLC added | 507,355 | $14M | 0.5% | 2025-Q1 stale |
| ANCHOR CAPITAL MANAGEMENT COMPANY, LLC trimmed | 735,366 | $13M | 0.5% | 2025-Q3 stale |
| M&G PLC new | 680,857 | $12M | 0.4% | 2025-Q3 stale |
| Trexquant Investment LP trimmed | 531,620 | $9M | 0.3% | 2025-Q4 stale |
| Qube Research & Technologies Ltd added | 506,601 | $9M | 0.3% | 2025-Q4 stale |
| Maxi Investments CY Ltd new | 424,000 | $7M | 0.3% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 353,826 | $6M | 0.2% | 2025-Q4 stale |
| HRT FINANCIAL LP added | 202,938 | $6M | 0.2% | 2025-Q2 stale |
| California Public Employees Retirement System added | 195,045 | $6M | 0.2% | 2025-Q2 stale |
| LBP AM SA added | 182,071 | $5M | 0.2% | 2025-Q2 stale |
| Crossmark Global Holdings, Inc. trimmed | 291,486 | $5M | 0.2% | 2025-Q4 stale |
| CIBC WORLD MARKET INC. added | 158,888 | $4M | 0.2% | 2025-Q1 stale |
| DARK FOREST CAPITAL MANAGEMENT LP trimmed | 248,011 | $4M | 0.2% | 2025-Q4 stale |
| Graphene Investments SAS new | 115,300 | $3M | 0.1% | 2025-Q2 stale |
| BAMCO INC /NY/ trimmed | 200,000 | $3M | 0.1% | 2025-Q4 stale |
| Private Advisor Group, LLC trimmed | 109,974 | $3M | 0.1% | 2025-Q2 stale |
| Corebridge Financial, Inc. trimmed | 120,352 | $3M | 0.1% | 2025-Q1 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.