Magnite

MGNI • NASDAQ

Magnite is a advertising agencies company in the communication services sector on NASDAQ, led by Michael G. Barrett, with a market cap of $2.3B. As of Q3 2025, 97% of shares are held by 308 institutional investors, with FMR LLC as the largest holder at 12.04%.

Chief Executive OfficerMichael G. Barrett

Market Cap$2.3B

Advertising Agencies

Communication Services

Employees911.0

Websiteinvestor.magnite.com

Country

United States of America

Overview

Overview of institutional ownership in MGNI as of Q3 2025 with a market cap of $3.1B

All Institutions

Institutions: 308
Value Held: $3.0B
Shares Held: 138.0M
Avg Position: $9.7M
Median Position: $859.7K

Hedge Funds

Hedge Funds: 47
Value Held: $389.6M
Shares Held: 17.9M
Avg Position: $8.3M
Median Position: $3.2M

Ownership Breakdown

Institutional (non-HF)

84.26%

$2.6B

Hedge Funds

12.56%

$389.6M

Retail & Other

3.18%

$98.5M

Based on market cap of $3.1B as of Q3 2025. Institutional (non-HF) excludes hedge funds to avoid double counting.

Biggest Investors

Institutions with the largest positions in MGNI as of Q3 2025

Institution	Key People	Position Value	Ownership	Owned Since	Total AUM (Long)
FMR LLC Institution	-	$373.3M 0.02% of portfolio	12.04% 17.1M shares	Q4 2020 Held for 4y 11m	$1.92T
VANGUARD GROUP INC Institution	Salim Ramji CEO	$319.2M 0.00% of portfolio	10.29% 14.7M shares	Q2 2014 Held for 11y 5m	$6.69T
B BlackRock, Inc. Institution	-	$248.6M 0.00% of portfolio	8.01% 11.4M shares	Q2 2015 Held for 10y 5m	$5.67T
Capital Research Global Investors RIA/Wealth	Maria Alejandra Herrera CIO	$152.1M 0.03% of portfolio	4.90% 7.0M shares	Q4 2024 Held for 11 months	$532.36B
WELLINGTON MANAGEMENT CO LLP Long Only Manager	Jean Marie Hynes CEO	$112.0M 0.02% of portfolio	3.61% 5.1M shares	Q3 2022 Held for 3y 2m	$571.21B
A AMERICAN CENTURY COMPANIES INC Institution	-	$100.1M 0.05% of portfolio	3.23% 4.6M shares	Q4 2022 Held for 2y 11m	$195.93B
Robeco Investment Management, Inc. Long Only Manager	Joseph Francis Feeney CEO	$95.2M 0.10% of portfolio	3.12% 4.4M shares	Q2 2024 Held for 1y 5m	$97.8B
GRANAHAN INVESTMENT MANAGEMENT INC/MA Long Only Manager	Jane Moran White CEO	$84.4M 3.45% of portfolio	2.72% 3.9M shares	Q4 2018 Held for 6y 11m	$2.4B
DIMENSIONAL FUND ADVISORS LP Long Only Manager	David Paul Butler CEO	$77.7M 0.02% of portfolio	2.51% 3.6M shares	Q1 2016 Held for 9y 8m	$466.32B
GEODE CAPITAL MANAGEMENT LLC ETF Provider	David Kenneth Lane CEO	$74.0M 0.00% of portfolio	2.39% 3.4M shares	Q2 2014 Held for 11y 5m	$1.57T

Net Capital Flow

Institutional buying and selling activity for MGNI in Q3 2025

Traded: −$202.6M
Buyers: 150
Sellers: 161
Total Bought: +$369.4M
Total Sold: −$572.0M
Avg Position: $8.7M

Biggest Buyers

Institution	Net Bought	Current Position
PRICE T ROWE ASSOCIATES INC /MD/ Long Only Manager	+$52.9M +2.4M shares	$55.5M 2.5M shares
Blue Grotto Capital, LLC Hedge Fund•Long/Short	+$27.5M +1.3M shares	$33.7M 1.5M shares
VANGUARD GROUP INC Institution	+$23.8M +1.1M shares	$319.2M 14.7M shares
T T. Rowe Price Investment Management, Inc. Insurance Manager	+$19.4M +890.9K shares	$19.4M 890.9K shares
MORGAN STANLEY RIA/Wealth	+$19.1M +875.7K shares	$44.6M 2.0M shares
J JANE STREET GROUP, LLC Institution	+$17.6M +806.3K shares	$23.8M 1.1M shares
B BlackRock, Inc. Institution	+$15.6M +715.1K shares	$248.6M 11.4M shares
MILLENNIUM MANAGEMENT LLC Hedge Fund•Multi-Strategy	+$14.7M +676.3K shares	$14.7M 676.3K shares
3 325 CAPITAL LLC Hedge Fund•Value	+$14.2M +650.1K shares	$14.2M 650.1K shares
GOLDMAN SACHS GROUP INC Institution	+$10.2M +470.0K shares	$52.0M 2.4M shares

Biggest Sellers

Institution	Net Sold	Current Position
Capital Research Global Investors RIA/Wealth	−$129.3M −5.9M shares	$152.1M 7.0M shares
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	−$45.8M −1.9M shares	Sold Off 0 shares
E Edenbrook Capital, LLC Hedge Fund•Value	−$32.7M −1.5M shares	$46.0M 2.1M shares
DIMENSIONAL FUND ADVISORS LP Long Only Manager	−$29.1M −1.3M shares	$77.7M 3.6M shares
UBS Group AG Institution	−$28.5M −1.3M shares	$9.3M 425.3K shares
DRIEHAUS CAPITAL MANAGEMENT LLC Hedge Fund•Event Driven	−$27.6M −1.3M shares	$33.0M 1.5M shares
Robeco Investment Management, Inc. Long Only Manager	−$24.1M −1.1M shares	$95.2M 4.4M shares
P Pacer Advisors, Inc. Institution	−$19.1M −791.8K shares	Sold Off 0 shares
BALYASNY ASSET MANAGEMENT LLC Hedge Fund•Multi-Strategy	−$16.9M −699.9K shares	Sold Off 0 shares
FRONTIER CAPITAL MANAGEMENT CO LLC Long Only Manager	−$15.3M −700.6K shares	$23.8M 1.1M shares

Entry and Exit Activity

Institutions that initiated new positions or completely exited MGNI in Q3 2025

New Positions: 25
New Value: $46.1M
Exited Positions: 38
Exited Value: $104.6M

New Positions

Institution	Position Value
T T. Rowe Price Investment Management, Inc. Insurance Manager	$19.4M 890.9K shares
3 325 CAPITAL LLC Hedge Fund•Value	$14.2M 650.1K shares
Bridgewater Associates, LP Hedge Fund•Global Macro	$3.2M 145.7K shares
NLI INTERNATIONAL INC Insurance Manager	$2.6M 120.4K shares
S STEINBERGANNA WEALTH MANAGEMENT RIA/Wealth	$1.5M 69.0K shares
RE ADVISERS CORP RIA/Wealth	$956.1K 43.9K shares
SIERRA SUMMIT ADVISORS LLC RIA/Wealth	$754.3K 34.6K shares
Jain Global LLC Hedge Fund•Multi-Strategy	$706.7K 32.4K shares
T TD ASSET MANAGEMENT INC Institution	$669.5K 30.7K shares
T TEACHERS RETIREMENT SYSTEM OF THE STATE OF KENTUCKY Institution	$548.9K 25.2K shares

Exited Positions

Institution	Previous Position
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	$45.8M 1.9M shares
P Pacer Advisors, Inc. Institution	$19.1M 791.8K shares
BALYASNY ASSET MANAGEMENT LLC Hedge Fund•Multi-Strategy	$16.9M 699.9K shares
R Roubaix Capital, LLC Hedge Fund•Long/Short	$6.3M 260.7K shares
Connor, Clark & Lunn Investment Management Ltd. Long Only Manager	$5.4M 225.3K shares
PDT Partners, LLC Hedge Fund•Quant	$1.5M 63.4K shares
Weiss Asset Management LP Hedge Fund•Multi-Strategy	$1.4M 59.1K shares
ExodusPoint Capital Management, LP Hedge Fund•Multi-Strategy	$861.7K 35.7K shares
B Bayesian Capital Management, LP Hedge Fund•Quant	$815.3K 33.8K shares
Walleye Trading Advisors, LLC Hedge Fund•Multi-Strategy	$626.3K 26.0K shares

Options Activity

Institutions with the largest Call and Put options positions in MGNI as of Q3 2025

Call Positions: 22
Call Value: $110.7M
Put Positions: 16
Put Value: $81.2M

Call Positions

Institution	Position Value
Caption Management, LLC Hedge Fund•Long/Short	$36.4M 16.7K contracts
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$26.3M 12.1K contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$7.2M 3.3K contracts
J JANE STREET GROUP, LLC Institution	$6.5M 3.0K contracts
Walleye Trading LLC RIA/Wealth	$6.1M 2.8K contracts
P PEAK6 LLC Institution	$4.9M 2.3K contracts
W WOLVERINE TRADING, LLC Institution	$4.3M 1.9K contracts
ARDSLEY ADVISORY PARTNERS Hedge Fund•Long/Short	$4.2M 2.0K contracts
UBS Group AG Institution	$3.5M 1.6K contracts
CITIGROUP INC Institution	$2.3M 1.1K contracts

Put Positions

Institution	Position Value
S Squarepoint Ops LLC Hedge Fund•Quant	$38.3M 17.6K contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$10.7M 4.9K contracts
P PEAK6 LLC Institution	$10.4M 4.8K contracts
Caption Management, LLC Hedge Fund•Long/Short	$8.7M 4.0K contracts
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$4.4M 2.0K contracts
J JANE STREET GROUP, LLC Institution	$2.8M 1.3K contracts
Walleye Trading LLC RIA/Wealth	$1.6M 752.0 contracts
Walleye Trading Advisors, LLC Hedge Fund•Multi-Strategy	$1.4M 644.0 contracts
W WOLVERINE TRADING, LLC Institution	$1.2M 522.0 contracts
C Cubist Systematic Strategies, LLC Institution	$481.3K 221.0 contracts

Most Committed Institutions

Institutions with MGNI as the highest % of their portfolio as of Q3 2025

Institution	Key People	Portfolio Weight	Ownership	Owned Since	Total AUM (Long)
E Edenbrook Capital, LLC Hedge Fund•Value	Jonathan Barry Brolin Managing Partner	23.36% $46.0M	1.48% 2.1M shares	Q2 2020 Held for 5y 5m	$196.7M
Nine Ten Capital Management LLC Hedge Fund•Long/Short	Russell Chad Mollen President	16.05% $62.3M	2.01% 2.9M shares	Q2 2020 Held for 5y 5m	$388.0M
N Norwood Investment Partners, LP Hedge Fund•Long/Short	Charles Hamilton Hoeveler Managing Partner	8.05% $9.4M	0.30% 430.0K shares	Q2 2025 Held for 5 months	$116.3M
Maestria Partners LLC Hedge Fund•Value	James Richard Edwards Managing Partner	7.86% $24.9M	0.80% 1.1M shares	Q4 2024 Held for 11 months	$316.4M
G GRIZZLYROCK CAPITAL, LLC Hedge Fund•Value	Michael Timothy Holt Member	6.61% $8.5M	0.27% 390.9K shares	Q4 2023 Held for 1y 11m	$128.8M
Meros Investment Management, LP Long Only Manager	Kenneth Scott Canon CEO	5.71% $13.4M	0.43% 613.8K shares	Q4 2021 Held for 3y 11m	$234.2M
3 325 CAPITAL LLC Hedge Fund•Value	Michael Braner Managing Partner	4.30% $14.2M	0.46% 650.1K shares	Q3 2025 Held for 2 months	$329.1M
P P.A.W. CAPITAL CORP Hedge Fund•Long/Short	Peter Allen Wright CEO	3.95% $2.2M	0.07% 100.0K shares	Q3 2018 Held for 7y 2m	$55.2M
Blue Grotto Capital, LLC Hedge Fund•Long/Short	Phillip Greg Deese CFO	3.91% $33.7M	1.09% 1.5M shares	Q2 2025 Held for 5 months	$862.3M
APIS CAPITAL ADVISORS, LLC Hedge Fund•Long/Short	Daniel James Barker CIO	3.88% $18.3M	0.59% 839.4K shares	Q2 2025 Held for 5 months	$471.4M

Hedge Fund Spotlight

Discover hedge funds investing in MGNI

Squarepoint Ops LLC

Hedge Fund • Quant

Portfolio ManagerMichael Gottlieb

Portfolio Value: $46.9B
Positions: 2,529
Last Reported: Q3 2025

Sector Allocation

Position in Magnite

Market Value: $3.6M
Shares Held: 166.5K
Portfolio Weight: 0.01%
Owned Since: 2023-Q2

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