Who owns MediaAlpha (MAX)
Which tracked institutional funds hold MAX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MAX company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 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
45 tracked funds added or opened MAX while 16 trimmed or exited it between 2026-Q1 and 2026-Q2 — 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
MAX’s largest tracked holder by dollar value, WHITE MOUNTAINS INSURANCE GROUP LTD, sizes it at 57.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 57.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in MAX 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 2026-Q1 and 2026-Q2, across 148 tracked filers holding MAX, 64 increased or opened the position and 102 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
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 MAX between the 2026-Q1 and 2026-Q2 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 5
- EVR Research LP$6M
- STIFEL FINANCIAL CORP$2M
- Walleye Capital LLC$1M
- WINMILL & CO. INC$818K
- Hillsdale Investment Management Inc.$577K
Full exits 7
- Pacer Advisors, Inc.$8M
- ACADIAN ASSET MANAGEMENT LLC$8M
- Philadelphia Financial Management of San Francisco, LLC$4M
- HRT FINANCIAL LP$3M
- Y-Intercept (Hong Kong) Ltd$1M
- GSA CAPITAL PARTNERS LLP$1M
Largest adds
- WHITE MOUNTAINS INSURANCE GROUP LTD$58M
- Divisadero Street Capital Management, LP$12M
- BlackRock, Inc.$10M
- Clearline Capital LP$10M
- JPMORGAN CHASE & CO$7M
- CITADEL ADVISORS LLC$5M
Largest trims
- Triad Investment Management$5M
- J. Goldman & Co LP$3M
- Qube Research & Technologies Ltd$3M
- FRANKLIN RESOURCES INC$2M
- SUSQUEHANNA INTERNATIONAL GROUP, LLP$1M
- UBS Group AG$1M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| WHITE MOUNTAINS INSURANCE GROUP LTD | 17,856,614 | $224M | 38.0% | 2026-Q2 |
| BlackRock, Inc. trimmed | 3,392,357 | $43M | 7.2% | 2026-Q2 |
| Clearline Capital LP added | 2,713,890 | $34M | 5.8% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 1,880,062 | $23M | 3.9% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC trimmed | 1,276,369 | $16M | 2.7% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 1,068,308 | $13M | 2.3% | 2026-Q2 |
| Divisadero Street Capital Management, LP added | 1,019,988 | $13M | 2.2% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 971,232 | $12M | 2.1% | 2026-Q2 |
| JACOBS ASSET MANAGEMENT, LLC trimmed | 919,761 | $12M | 2.0% | 2026-Q2 |
| STATE STREET CORP added | 862,235 | $11M | 1.8% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 829,958 | $10M | 1.8% | 2026-Q2 |
| MORGAN STANLEY added | 821,170 | $10M | 1.7% | 2026-Q2 |
| Nuveen, LLC added | 752,447 | $9M | 1.6% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 701,914 | $9M | 1.5% | 2026-Q2 |
| J. Goldman & Co LP trimmed | 598,070 | $8M | 1.3% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 589,696 | $7M | 1.3% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 574,407 | $7M | 1.2% | 2026-Q2 |
| Shay Capital LLC trimmed | 570,000 | $7M | 1.2% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 551,625 | $7M | 1.2% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 535,926 | $7M | 1.1% | 2026-Q2 |
| SPEECE THORSON CAPITAL GROUP INC trimmed | 489,098 | $6M | 1.0% | 2026-Q2 |
| EVR Research LP new | 440,000 | $6M | 0.9% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC trimmed | 433,046 | $5M | 0.9% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 428,866 | $5M | 0.9% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 409,480 | $5M | 0.9% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 391,641 | $5M | 0.8% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ added | 371,840 | $5M | 0.8% | 2026-Q2 |
| Triad Investment Management trimmed | 368,731 | $5M | 0.8% | 2026-Q2 |
| Stoic Point Capital Management LLC added | 297,150 | $4M | 0.6% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 267,107 | $3M | 0.6% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 259,224 | $3M | 0.6% | 2026-Q2 |
| Squarepoint Ops LLC added | 234,255 | $3M | 0.5% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO trimmed | 223,917 | $3M | 0.5% | 2026-Q2 |
| TEACHER RETIREMENT SYSTEM OF TEXAS added | 216,405 | $3M | 0.5% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 211,450 | $2M | 0.3% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS added | 209,204 | $3M | 0.4% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 180,171 | $2M | 0.4% | 2026-Q2 |
| XTX Topco Ltd added | 172,269 | $2M | 0.4% | 2026-Q2 |
| ALGERT GLOBAL LLC added | 170,870 | $2M | 0.4% | 2026-Q2 |
| Man Group plc added | 156,754 | $2M | 0.3% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC added | 148,845 | $2M | 0.3% | 2026-Q2 |
| Quantinno Capital Management LP added | 136,034 | $2M | 0.3% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 130,360 | $2M | 0.3% | 2026-Q2 |
| STIFEL FINANCIAL CORP new | 126,175 | $2M | 0.3% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC added | 101,365 | $1M | 0.2% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 101,046 | $1M | 0.2% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 92,453 | $1M | 0.2% | 2026-Q2 |
| PDT Partners, LLC trimmed | 84,022 | $1M | 0.2% | 2026-Q2 |
| Bank of New York Mellon Corp trimmed | 81,504 | $1M | 0.2% | 2026-Q2 |
| Walleye Capital LLC added | 80,306 | $1M | 0.2% | 2026-Q2 |
| FRANKLIN RESOURCES INC trimmed | 74,587 | $938K | 0.2% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 70,309 | $884K | 0.1% | 2026-Q2 |
| Allianz Asset Management GmbH | 70,176 | $653K | 0.1% | 2026-Q2 |
| WINMILL & CO. INC new | 65,102 | $818K | 0.1% | 2026-Q2 |
| Swiss National Bank added | 60,800 | $764K | 0.1% | 2026-Q2 |
| BLAIR WILLIAM & CO/IL added | 56,046 | $704K | 0.1% | 2026-Q2 |
| GLOBEFLEX CAPITAL L P trimmed | 55,850 | $702K | 0.1% | 2026-Q2 |
| Campbell & CO Investment Adviser LLC added | 46,617 | $586K | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS trimmed | 45,932 | $577K | 0.1% | 2026-Q2 |
| Hillsdale Investment Management Inc. trimmed | 45,900 | $577K | 0.1% | 2026-Q2 |
| Allspring Global Investments Holdings, LLC trimmed | 44,831 | $564K | 0.1% | 2026-Q2 |
| SEI INVESTMENTS CO added | 44,637 | $561K | 0.1% | 2026-Q2 |
| Mariner, LLC trimmed | 41,127 | $517K | 0.1% | 2026-Q2 |
| Caption Management, LLC trimmed | 37,515 | $472K | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ | 37,076 | $467K | 0.1% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 37,065 | $466K | 0.1% | 2026-Q2 |
| DEUTSCHE BANK AG\ trimmed | 34,254 | $431K | 0.1% | 2026-Q2 |
| Lighthouse Investment Partners, LLC trimmed | 34,001 | $427K | 0.1% | 2026-Q2 |
| UBS Group AG trimmed | 33,602 | $422K | 0.1% | 2026-Q2 |
| BARCLAYS PLC trimmed | 30,349 | $381K | 0.1% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 28,163 | $354K | 0.1% | 2026-Q2 |
| Legal & General Group Plc | 27,533 | $346K | 0.1% | 2026-Q2 |
| Brevan Howard Capital Management LP added | 27,117 | $341K | 0.1% | 2026-Q2 |
| Dynamic Technology Lab Private Ltd trimmed | 26,868 | $338K | 0.1% | 2026-Q2 |
| FMR LLC trimmed | 26,386 | $332K | 0.1% | 2026-Q2 |
| Invesco Ltd. added | 26,039 | $327K | 0.1% | 2026-Q2 |
| TUDOR INVESTMENT CORP ET AL trimmed | 25,748 | $324K | 0.1% | 2026-Q2 |
| ALLSTATE CORP new | 25,287 | $318K | 0.1% | 2026-Q2 |
| AXQ CAPITAL, LP added | 25,117 | $316K | 0.1% | 2026-Q2 |
| Abel Hall, LLC trimmed | 24,473 | $308K | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM trimmed | 24,141 | $303K | 0.1% | 2026-Q2 |
| CITIGROUP INC added | 24,003 | $302K | 0.1% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 23,247 | $292K | 0.0% | 2026-Q2 |
| Corient Private Wealth LP added | 23,013 | $289K | 0.0% | 2026-Q2 |
| Quantbot Technologies LP trimmed | 21,568 | $271K | 0.0% | 2026-Q2 |
| MetLife Investment Management, LLC | 21,402 | $269K | 0.0% | 2026-Q2 |
| JUPITER ASSET MANAGEMENT LTD | 21,172 | $266K | 0.0% | 2026-Q2 |
| Zurcher Kantonalbank (Zurich Cantonalbank) | 18,642 | $234K | 0.0% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd | 17,425 | $219K | 0.0% | 2026-Q2 |
| Graham Capital Management, L.P. added | 17,179 | $216K | 0.0% | 2026-Q2 |
| MERCER GLOBAL ADVISORS INC /ADV added | 16,595 | $209K | 0.0% | 2026-Q2 |
| Creative Planning trimmed | 16,220 | $204K | 0.0% | 2026-Q2 |
| NOMURA HOLDINGS INC trimmed | 16,058 | $202K | 0.0% | 2026-Q2 |
| IEQ CAPITAL, LLC trimmed | 15,367 | $193K | 0.0% | 2026-Q2 |
| EP Wealth Advisors, LLC new | 15,273 | $192K | 0.0% | 2026-Q2 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC trimmed | 14,811 | $198K | 0.0% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. trimmed | 14,208 | $179K | 0.0% | 2026-Q2 |
| Jupiter Topco LLC new | 13,862 | $174K | 0.0% | 2026-Q2 |
| Cerity Partners LLC trimmed | 13,617 | $171K | 0.0% | 2026-Q2 |
| LPL Financial LLC added | 13,300 | $167K | 0.0% | 2026-Q2 |
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.