MGNI · Magnite, Inc. · Shareholders & Ownership
Every disclosed holder of MGNI in one list: 13F institutions, Schedule 13D and 13G filers, insiders (Forms 3, 4 and 5) and registered funds, each from its own latest filing. Holders nest by CIK and SEC reporting links, never by name, and each is summed once.
Who Owns MGNI
13F quarter Sep 30, 2026, combined view: filers that have not filed yet carry their Jun 30, 2026 positionsNo chart: the summed disclosures exceed shares outstanding, so they are not parts of one whole.
| Holder group | Shares | % Out |
|---|---|---|
| Institutional (13F) | 141,741,515 | 98.83% |
| Insiders (Forms 3, 4, 5) | 3,549,804 | 2.48% |
| 13D/G-only blocks | 0 | 0.00% |
| Remaining | 1,867,162 | -1.30% |
| Registered funds (N-PORT, not summed) | 58,368,731 | 40.70% |
Shares outstanding: 143,424,157, the issuer's latest cover-page count restated onto today's split basis.
Remaining is negative: the summed disclosures exceed shares outstanding, as when filings are dated at different times or holders that do not disclose their links count the same shares. It is flagged, not clipped.
13D/G-only counts each filer's latest 13D or 13G that no 13F report of the listing contains, that names no 13F filer and that no counted insider files. Funds are never summed: their shares sit inside their advisers' 13F reports.
Holders of MGNI
| # | Holder | Shares | As of | Notes |
|---|---|---|---|---|
| 1 |
BlackRock, Inc.
13F
CIK 2012383 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
12,713,156 | ||
| 1.1 |
iShares Russell 2000 ETF
Fund
S000004344 · Registered fund · Jun 30, 2026
iShares Trust, not summed
|
3,706,804 | ||
| 1.2 |
iShares Russell 2000 Growth ETF
Fund
S000004343 · Registered fund · Jun 30, 2026
iShares Trust, not summed
|
778,141 | ||
| 1.3 |
iShares Russell 2000 Value ETF
Fund
S000004342 · Registered fund · Jun 30, 2026
iShares Trust, not summed
|
565,202 | ||
| 1.4 |
BlackRock Advantage Small Cap Core Fund
Fund
S000039982 · Registered fund · May 29, 2026
BlackRock Funds, not summed
|
267,915 | ||
| 1.5 |
Master Small Cap Index Series
Fund
S000002716 · Registered fund · Jun 30, 2026
Quantitative Master Series LLC, not summed
|
263,665 | ||
| 2 |
VANGUARD PORTFOLIO MANAGEMENT LLC
13F
CIK 2100121 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
8,197,286 | ||
| 3 |
FMR LLC
13F
CIK 315066 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
7,759,426 | ||
| 3.1 |
FMR LLC
13G
CIK 315066 · Holding company · Jun 30, 2026
Rule 13d-1(b), qualified institution, not summed
|
7,759,425 | ||
| 3.2 |
Fidelity Small Cap Index Fund
Fund
S000033638 · Registered fund · Jul 31, 2026
Fidelity Salem Street Trust, not summed
|
1,579,669 | ||
| 3.3 |
Select Communication Services Portfolio
Fund
S000007476 · Registered fund · May 31, 2026
Fidelity Select Portfolios, not summed
|
1,472,463 | ||
| 3.4 |
Fidelity Balanced Fund
Fund
S000007151 · Registered fund · May 31, 2026
Fidelity Puritan Trust, not summed
|
1,288,989 | ||
| 3.5 |
Fidelity Small Cap Growth Fund
Fund
S000007193 · Registered fund · Jul 31, 2026
Fidelity Securities Fund, not summed
|
1,117,610 | ||
| 4 |
VANGUARD CAPITAL MANAGEMENT LLC
13F
CIK 2100119 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
6,225,195 | ||
| 5 |
WELLINGTON MANAGEMENT GROUP LLP
13F
CIK 902219 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
6,044,492 | ||
| 5.1 |
WELLINGTON MANAGEMENT GROUP LLP
13G
CIK 902219 · Holding company · Jun 30, 2026
Rule 13d-1(b), qualified institution, not summed
|
6,044,492 | ||
| 6 |
DIMENSIONAL FUND ADVISORS LP
13F
CIK 354204 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
5,260,132 | ||
| 6.1 |
U.S. SMALL CAP VALUE PORTFOLIO
Fund
S000000987 · Registered fund · Jul 31, 2026
DFA INVESTMENT DIMENSIONS GROUP INC, not summed
|
768,060 | ||
| 6.2 |
U.S. SMALL CAP PORTFOLIO
Fund
S000000971 · Registered fund · Jul 31, 2026
DFA INVESTMENT DIMENSIONS GROUP INC, not summed
|
628,087 | ||
| 6.3 |
Dimensional U.S. Small Cap ETF
Fund
S000070906 · Registered fund · Jul 31, 2026
Dimensional ETF Trust, not summed
|
495,924 | ||
| 6.4 |
U.S. MICRO CAP PORTFOLIO
Fund
S000000948 · Registered fund · Jul 31, 2026
DFA INVESTMENT DIMENSIONS GROUP INC, not summed
|
435,680 | ||
| 6.5 |
Dimensional US Small Cap Value ETF
Fund
S000075151 · Registered fund · Jul 31, 2026
Dimensional ETF Trust, not summed
|
378,106 | ||
| 7 |
Boston Partners
13F
CIK 1386060 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
5,013,835 | ||
| 8 |
AMERICAN CENTURY COMPANIES INC
13F
CIK 748054 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
4,622,736 | ||
| 8.1 |
Small Cap Growth Fund
Fund
S000006193 · Registered fund · Jul 31, 2026
American Century Mutual Funds, Inc., not summed
|
2,943,653 | ||
| 8.2 |
Global Small Cap Fund
Fund
S000053103 · Registered fund · May 31, 2026
American Century World Mutual Funds, Inc., not summed
|
12,562 | ||
| 9 |
VANGUARD TOTAL STOCK MARKET INDEX FUND
Fund
S000002848 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
|
4,326,601 | ||
| 10 |
Capital Research Global Investors
13F
CIK 1422848 · Investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
3,869,159 | ||
| 11 |
SMALLCAP World Fund Inc
Fund
S000009599 · Registered fund · Jun 30, 2026
SMALLCAP World Fund Inc, not summed
|
3,796,613 | ||
| 12 |
|
3,794,811 | ||
| 12.1 |
College Retirement Equities Fund - Total Global Stock Account
Fund
S000005080 · Registered fund · Jun 30, 2026
College Retirement Equities Fund, not summed
|
1,484,347 | ||
| 12.2 |
Nuveen Quant Small Cap Equity Fund
Fund
S000005386 · Registered fund · Jul 31, 2026
TIAA-CREF Funds, not summed
|
727,550 | ||
| 12.3 |
Nuveen Quant Small/Mid Cap Equity Fund
Fund
S000054623 · Registered fund · Jul 31, 2026
TIAA-CREF Funds, not summed
|
304,380 | ||
| 12.4 |
Nuveen Small Cap Select Fund
Fund
S000005569 · Registered fund · Jul 31, 2026
Nuveen Investment Funds, Inc., not summed
|
260,918 | ||
| 12.5 |
Nuveen Small Cap Growth Opportunities Fund
Fund
S000005567 · Registered fund · Jul 31, 2026
Nuveen Investment Funds, Inc., not summed
|
227,121 | ||
| 13 |
GEODE CAPITAL MANAGEMENT, LLC
13F
CIK 1214717 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
3,789,959 | ||
| 14 |
Edenbrook Capital, LLC
13F
CIK 1666682 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
3,555,615 | ||
| 15 |
|
3,528,075 | ||
| 15.1 |
STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO
Fund
S000050332 · Registered fund · Jun 30, 2026
STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
|
50,327 | ||
| 15.2 |
State Street(R) SPDR(R) Portfolio MSCI Global Stock Market ETF
Fund
S000036082 · Registered fund · Jun 30, 2026
SPDR INDEX SHARES FUNDS, not summed
|
7,338 | ||
| 15.3 |
State Street Total Return V.I.S. Fund
Fund
S000001637 · Registered fund · Jun 30, 2026
STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed
|
3,646 | ||
| 15.4 |
State Street Balanced Index Fund
Fund
S000082802 · Registered fund · Jun 30, 2026
STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
|
740 | ||
| 16 |
325 CAPITAL LLC
13F
CIK 1873893 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
3,412,694 | ||
| 17 |
Nine Ten Capital Management LLC
13F
CIK 1635236 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
3,261,283 | ||
| 18 |
VANGUARD SMALL-CAP INDEX FUND
Fund
S000002845 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
|
3,116,881 | ||
| 19 |
Granahan Investment Management, LLC
13F
CIK 1026710 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
3,083,211 | ||
| 20 |
CANADA PENSION PLAN INVESTMENT BOARD
13F
CIK 1283718 · Non-US institution · Jun 30, 2026
carried, not yet filed for the newest quarter
|
2,995,093 | ||
| 21 |
JANE STREET GROUP, LLC
13F
CIK 1595888 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
2,199,191 | ||
| 22 |
Park West Asset Management LLC
13F
CIK 1386928 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
2,000,000 | ||
| 23 |
MORGAN STANLEY
13F
CIK 895421 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,991,732 | ||
| 23.1 |
E*TRADE No Fee Total Market Index Fund
Fund
S000090722 · Registered fund · Jul 31, 2026
E Trade Trust, not summed
|
92 | ||
| 24 |
VANGUARD SMALL-CAP VALUE INDEX FUND
Fund
S000002847 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
|
1,976,558 | ||
| 25 |
Qube Research & Technologies Ltd
13F
CIK 1729829 · Exempt reporting adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,955,989 | ||
| 26 |
Blue Grotto Capital, LLC
13F
CIK 1764725 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,706,741 | ||
| 27 |
KENNEDY CAPITAL MANAGEMENT LLC
13F
CIK 884589 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,666,799 | ||
| 27.1 |
Kennedy Capital Small Cap Growth Fund
Fund
S000076117 · Registered fund · Jun 30, 2026
INVESTMENT MANAGERS SERIES TRUST II, not summed
|
904 | ||
| 28 |
VANGUARD EXTENDED MARKET INDEX FUND
Fund
S000002841 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
|
1,644,422 | ||
| 29 |
NORTHERN TRUST CORP
13F
CIK 73124 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,553,412 | ||
| 29.1 |
Small Cap Value Fund
Fund
S000001246 · Registered fund · Jun 30, 2026
Northern Funds, not summed
|
125,471 | ||
| 29.2 |
Small Cap Index Fund
Fund
S000001245 · Registered fund · Jun 30, 2026
Northern Funds, not summed
|
73,169 | ||
| 29.3 |
Small Cap Core Fund
Fund
S000001244 · Registered fund · Jun 30, 2026
Northern Funds, not summed
|
7,213 | ||
| 29.4 |
FlexShares Morningstar US Market Factor Tilt Index Fund
Fund
S000033312 · Registered fund · Jul 31, 2026
FlexShares Trust, not summed
|
4,212 | ||
| 30 |
ROYCE & ASSOCIATES LP
13F
CIK 906304 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,473,397 | ||
| 30.1 |
Royce Smaller-Companies Growth Fund
Fund
S000009517 · Registered fund · Jun 30, 2026
ROYCE FUND, not summed
|
355,000 | ||
| 30.2 |
Royce Small-Cap Opportunity Fund
Fund
S000009512 · Registered fund · Jun 30, 2026
ROYCE FUND, not summed
|
289,782 | ||
| 30.3 |
Royce Micro-Cap Fund
Fund
S000009506 · Registered fund · Jun 30, 2026
ROYCE FUND, not summed
|
94,935 | ||
| 30.4 |
Royce Capital Fund - Micro-Cap Portfolio
Fund
S000009496 · Registered fund · Jun 30, 2026
ROYCE CAPITAL FUND, not summed
|
29,416 | ||
| 31 |
GOLDMAN SACHS GROUP INC
13F
CIK 886982 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,466,640 | ||
| 31.1 |
Multi-Manager U.S. Small Cap Equity Fund
Fund
S000051363 · Registered fund · Apr 30, 2026
Goldman Sachs Trust II, not summed
|
106,945 | ||
| 31.2 |
Goldman Sachs Multi-Manager Global Equity Fund
Fund
S000049146 · Registered fund · Jul 31, 2026
Goldman Sachs Trust II, not summed
|
25,046 | ||
| 31.3 |
Goldman Sachs ActiveBeta(R) U.S. Small Cap Equity ETF
Fund
S000048296 · Registered fund · May 31, 2026
Goldman Sachs ETF Trust, not summed
|
18,315 | ||
| 31.4 |
Goldman Sachs Absolute Return Tracker Fund
Fund
S000020314 · Registered fund · Jun 30, 2026
GOLDMAN SACHS TRUST, not summed
|
2,288 | ||
| 32 |
Ophir Asset Management Pty Ltd
13F
CIK 1844640 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,450,061 | ||
| 33 |
VICTORY CAPITAL MANAGEMENT INC
13F
CIK 1040188 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,235,384 | ||
| 33.1 |
Victory Integrity Small-Cap Value Fund
Fund
S000046393 · Registered fund · Jun 30, 2026
Victory Portfolios, not summed
|
417,000 | ||
| 33.2 |
Victory Small Cap Stock Fund
Fund
S000012914 · Registered fund · Jul 31, 2026
Victory Portfolios III, not summed
|
354,313 | ||
| 33.3 |
VictoryShares Small Cap Free Cash Flow ETF
Fund
S000080690 · Registered fund · Jun 30, 2026
Victory Portfolios II, not summed
|
141,657 | ||
| 33.4 |
Victory Extended Market Index Fund
Fund
S000012941 · Registered fund · Jul 31, 2026
Victory Portfolios III, not summed
|
16,139 | ||
| 34 |
CHARLES SCHWAB INVESTMENT MANAGEMENT INC
13F
CIK 884546 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,203,189 | ||
| 34.1 |
Schwab U.S. Small-Cap ETF
Fund
S000026636 · Registered fund · May 31, 2026
SCHWAB STRATEGIC TRUST, not summed
|
693,882 | ||
| 34.2 |
Schwab Small-Cap Index Fund
Fund
S000005912 · Registered fund · Jul 31, 2026
SCHWAB CAPITAL TRUST, not summed
|
350,747 | ||
| 34.3 |
Schwab Total Stock Market Index Fund
Fund
S000005913 · Registered fund · Jul 31, 2026
SCHWAB CAPITAL TRUST, not summed
|
87,392 | ||
| 34.4 |
Schwab U.S. Broad Market ETF
Fund
S000026631 · Registered fund · May 31, 2026
SCHWAB STRATEGIC TRUST, not summed
|
83,766 | ||
| 35 |
BANK OF AMERICA CORP /DE/
13F
CIK 70858 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,181,832 | ||
| 36 |
GRIZZLYROCK CAPITAL, LLC
13F
CIK 2011732 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,164,628 | ||
| 37 |
Bank of New York Mellon Corp
13F
CIK 1390777 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,162,198 | ||
| 38 |
Maestria Partners LLC
13F
CIK 2000390 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,158,430 | ||
| 39 |
Meros Investment Management, LP
13F
CIK 1911372 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
991,335 | ||
| 40 |
VANGUARD FIDUCIARY TRUST CO
13F
CIK 933478 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
989,092 | ||
| 41 |
JNL Multi-Manager Small Cap Growth Fund
Fund
S000001776 · Registered fund · Jun 30, 2026
JNL Series Trust, not summed
|
868,393 | ||
| 42 |
MILLENNIUM MANAGEMENT LLC
13F
CIK 1273087 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
764,819 | ||
| 43 |
QVT Financial LP
13F
CIK 1290162 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
747,437 | ||
| 44 |
|
746,350 | ||
| 45 |
OBERWEIS ASSET MANAGEMENT INC/
13F
CIK 937886 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
735,000 | ||
| 45.1 |
Oberweis Micro-Cap Fund
Fund
S000010231 · Registered fund · Jun 30, 2026
OBERWEIS FUNDS, not summed
|
709,000 | ||
| 46 |
VANGUARD RUSSELL 2000 INDEX FUND
Fund
S000030003 · Registered fund · May 31, 2026
VANGUARD SCOTTSDALE FUNDS, not summed
|
731,075 | ||
| 47 |
SILVERCREST ASSET MANAGEMENT GROUP LLC
13F
CIK 1232395 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
707,749 | ||
| 48 |
Boston Partners Small Cap Value Fund II
Fund
S000001094 · Registered fund · May 31, 2026
RBB Fund, Inc., not summed
|
701,469 | ||
| 49 |
PICTON MAHONEY ASSET MANAGEMENT
13F
CIK 1539041 · Non-US institution · Jun 30, 2026
carried, not yet filed for the newest quarter
|
691,471 | ||
| 50 |
First Eagle Investment Management, LLC
13F
CIK 1325447 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
670,788 | ||
| 50.1 |
First Eagle Small Cap Opportunity Fund
Fund
S000072438 · Registered fund · Jul 31, 2026
First Eagle Funds, not summed
|
616,170 |
66 more nested rows are not shown here; Every filing lists them all.
Shares are restated onto today's split basis. Change compares each row with the same holder's previous filing in the same source; a dash means there is none to compare. Nested 13D/G, insider and fund rows are not summed, since a 13F report already holds them.
Showing 1–50 of 455 holders
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