Magnite Inc. (MGNI) Ownership
MGNI ownership summary
as of October 18, 2026- Institutions
- 100.6% of shares outstanding
- Insiders
- 1.20% of shares outstanding
- Shares outstanding
- 143.4M
- Float
- 141.7M shares available to trade
- Short interest
- 8.61% 10.9M shares short
- Days to cover
- 4.47 short interest down 4.4% vs prior month
- Institutions 100.57%
- Insiders 1.20%
MGNI top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 8.86% | 12.7M | $297.1M | +1.1M (+9.1%) | June 30, 2026 |
| 2 | Vanguard Portfolio Management, LLC | 5.72% | 8.2M | $191.6M | +471,081 (+6.1%) | June 30, 2026 |
| 3 | FMR Inc | 5.41% | 7.8M | $181.3M | +3.3M (+72.1%) | June 30, 2026 |
| 4 | Vanguard Capital Management, LLC | 4.34% | 6.2M | $145.5M | +34,792 (+0.6%) | June 30, 2026 |
| 5 | Wellington Management Company LLP | 4.21% | 6.0M | $141.3M | −3.1M (−34.2%) | June 30, 2026 |
| 6 | Dimensional Fund Advisors, Inc. | 3.67% | 5.3M | $122.9M | +1.3M (+32.0%) | June 30, 2026 |
| 7 | Boston Partners Global Investors, Inc | 3.50% | 5.0M | $117.2M | +293,972 (+6.2%) | June 30, 2026 |
| 8 | American Century Companies Inc | 3.22% | 4.6M | $108.0M | −4,080 (−0.1%) | June 30, 2026 |
| 9 | Capital Research Global Investors | 2.70% | 3.9M | $90.4M | −1.2M (−22.9%) | June 30, 2026 |
| 10 | Nuveen, LLC | 2.65% | 3.8M | $88.7M | +204,786 (+5.7%) | June 30, 2026 |
| 11 | Geode Capital Management, LLC | 2.64% | 3.8M | $88.6M | +236,169 (+6.6%) | June 30, 2026 |
| 12 | Edenbrook Capital LLC | 2.48% | 3.6M | $83.1M | +757,579 (+27.1%) | June 30, 2026 |
| 13 | State Street Corp | 2.46% | 3.5M | $82.5M | +364,936 (+11.5%) | June 30, 2026 |
| 14 | 325 Capital LLC | 2.38% | 3.4M | $79.8M | +1.4M (+70.2%) | June 30, 2026 |
| 15 | Nine Ten Capital Management LLC | 2.27% | 3.3M | $76.2M | −220,000 (−6.3%) | June 30, 2026 |
| 16 | Granahan Investment Management Inc.. | 2.15% | 3.1M | $72.1M | +529,798 (+20.7%) | June 30, 2026 |
| 17 | Canada Pension Plan Investment Board | 2.09% | 3.0M | $70.0M | +2.9M (+6,403.7%) | June 30, 2026 |
| 18 | Jane Street Group LLC | 1.53% | 2.2M | $51.4M | +531,031 (+31.8%) | June 30, 2026 |
| 19 | Park West Asset Management LLC | 1.39% | 2.0M | $46.7M | +1.4M (+234.2%) | June 30, 2026 |
| 20 | Morgan Stanley - Brokerage Accounts | 1.39% | 2.0M | $46.5M | +1.1M (+114.9%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 16 holders added 15.8M shares and 4 cut 4.5M.
MGNI top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 3.02% | 4.3M | $101.4M | −7,958 (−0.2%) | August 31, 2026 |
| 2 | American Funds SMALLCAP World A | 2.63% | 3.8M | $88.0M | −1.1M (−23.1%) | June 30, 2026 |
| 3 | iShares Russell 2000 ETF | 2.61% | 3.7M | $87.6M | −43,200 (−1.1%) | September 30, 2026 |
| 4 | Vanguard Small Cap Index | 2.18% | 3.1M | $73.1M | +1,962 (+0.1%) | August 31, 2026 |
| 5 | American Century Small Cap Growth Inv | 2.05% | 2.9M | $68.8M | +37,829 (+1.3%) | June 30, 2026 |
| 6 | Vanguard MStar Small Cap Value Index | 1.39% | 2.0M | $46.5M | +1,633 (+0.1%) | August 31, 2026 |
| 7 | Fidelity Small Cap Index | 1.10% | 1.6M | $36.9M | +13,453 (+0.9%) | July 31, 2026 |
| 8 | CREF Total Global Stock Account R3 | 0.91% | 1.3M | $30.4M | −184,336 (−12.4%) | July 31, 2026 |
| 9 | Fidelity Select Communication Services | 0.90% | 1.3M | $30.1M | — | August 31, 2026 |
| 10 | Fidelity Small Cap Growth | 0.78% | 1.1M | $26.1M | — | July 31, 2026 |
| 11 | Fidelity Balanced | 0.75% | 1.1M | $25.3M | −207,033 (−16.1%) | July 31, 2026 |
| 12 | JNL Multi-Manager Small Cap Growth A | 0.61% | 868K | $20.3M | +43,853 (+5.3%) | June 30, 2026 |
| 13 | Vanguard Russell 2000 ETF | 0.58% | 830K | $19.4M | +19,881 (+2.5%) | August 31, 2026 |
| 14 | iShares Russell 2000 Growth ETF | 0.55% | 790K | $18.5M | −1,000 (−0.1%) | September 30, 2026 |
| 15 | DFA US Small Cap Value I | 0.54% | 768K | $17.9M | — | August 31, 2026 |
| 16 | Schwab US Small-Cap ETF™ | 0.53% | 755K | $17.6M | +504 (+0.1%) | September 30, 2026 |
| 17 | Nuveen Quant Small Cap Equity R6 | 0.51% | 728K | $17.0M | — | August 31, 2026 |
| 18 | Oberweis Micro-Cap | 0.49% | 709K | $16.6M | +88,600 (+14.3%) | June 30, 2026 |
| 19 | Fidelity Extended Market Index | 0.49% | 699K | $16.3M | −12,396 (−1.7%) | August 31, 2026 |
| 20 | AZ Fd 1 - AZ Eq - Amer Opps A-EUR Acc | 0.45% | 644K | $15.1M | +13,714 (+2.2%) | July 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
MGNI insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-02-18 | Adam Lee Soroca | Sell | $12.00 | 21,529 | $258,348 |
| 2025-12-17 | Adam Lee Soroca | Sell | $17.00 | 16,656 | $283,152 |
| 2025-11-21 | Robert F Spillane | Sell | $14.22 | 12,500 | $177,750 |
| 2025-11-18 | Adam Lee Soroca | Sell | $13.23 | 10,857 | $143,638 |
| 2025-11-18 | Sean Patrick Buckley | Sell | $13.36 | 4,426 | $59,131 |
| 2025-10-24 | Paul Caine | Sell | $20.00 | 5,000 | $100,000 |
| 2025-09-19 | Aaron Saltz | Sell | $24.50 | 8,522 | $208,789 |
| 2025-09-19 | Paul Caine | Sell | $25.00 | 7,500 | $187,500 |
| 2025-09-15 | Aaron Saltz | Sell | $23.94 | 6,180 | $147,949 |
| 2025-09-10 | Paul Caine | Sell | $23.60 | 5,000 | $118,000 |
| 2025-09-08 | Sean Patrick Buckley | Sell | $25.56 | 20,000 | $511,200 |
| 2025-09-04 | Brian Gephart | Sell | $24.71 | 27,671 | $683,750 |
| 2025-09-03 | David Buonasera | Sell | $25.37 | 2,950 | $74,842 |
| 2025-09-02 | Adam Lee Soroca | Sell | $24.69 | 24,986 | $616,904 |
| 2025-08-29 | Aaron Saltz | Sell | $26.07 | 12,403 | $323,346 |
| 2025-08-27 | Katie Seitz Evans | Sell | $25.52 | 21,509 | $548,910 |
| 2025-08-26 | Diane Yu | Sell | $25.23 | 20,000 | $504,600 |
| 2025-08-25 | Katie Seitz Evans | Sell | $26.00 | 8,345 | $216,970 |
| 2025-08-25 | Paul Caine | Sell | $25.00 | 7,500 | $187,500 |
| 2025-08-19 | Adam Lee Soroca | Sell | $23.47 | 10,579 | $248,289 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
MGNI shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns MGNI
Institutional investors own 100.6% of Magnite's shares and insiders 1.20%. The largest holder is BlackRock Inc with 8.86% of the shares (12.7M), as of June 30, 2026. Among the top 20 institutions, 16 added shares and 4 reduced their stake in the latest filings. Short interest is 8.61% of the float, or 4.47 days of average trading volume. The share count rose 310.9% since 2014.
Related: MGNI analyst forecast, MGNI key metrics. See the MGNI stock overview for the latest quote and news.
MGNI ownership FAQ
Who owns the most Magnite stock?
The largest shareholders of Magnite are BlackRock Inc (8.86%), Vanguard Portfolio Management, LLC (5.72%), FMR Inc (5.41%), Vanguard Capital Management, LLC (4.34%), Wellington Management Company LLP (4.21%).
What percentage of Magnite is owned by institutions?
Institutions hold 100.6% of Magnite's shares outstanding; insiders hold 1.20%.
Which funds own Magnite?
The largest fund holders of Magnite are Vanguard MStar Total Stk Mkt Idx Invest (3.02%), American Funds SMALLCAP World A (2.63%), iShares Russell 2000 ETF (2.61%), Vanguard Small Cap Index (2.18%), American Century Small Cap Growth Inv (2.05%).
What is Magnite's short interest?
10.9M shares of Magnite were sold short, 8.61% of the float; at the average daily volume it would take 4.47 days to cover.
Are insiders buying or selling Magnite?
Of the latest 20 reported insider transactions in Magnite (since August 19, 2025), 0 were purchases and 20 were sales.
How many shares of Magnite are outstanding?
Magnite has 143.4M shares outstanding, of which 141.7M are in the public float.