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Institutional Ownership · SEC Form 13F

Who owns MediaAlpha, Inc. (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-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.

163
Institutional holders
49M
Shares held (tracked funds)

How the tape is positioned

24 tracked funds added or opened MAX while 53 trimmed or exited it between 2025-Q4 and 2026-Q1 — 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 53.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 53.0pp 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 2025-Q4 and 2026-Q1, across 163 tracked filers holding MAX, 93 increased or opened the position and 100 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.

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 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 7

  • VANGUARD CAPITAL MANAGEMENT LLC$13M
  • VANGUARD PORTFOLIO MANAGEMENT LLC$5M
  • SPEECE THORSON CAPITAL GROUP INC$5M
  • Philadelphia Financial Management of San Francisco, LLC$4M
  • VANGUARD FIDUCIARY TRUST CO$2M
  • Caption Management, LLC$1M

Full exits 12

  • VANGUARD GROUP INC$30M
  • G2 Investment Partners Management LLC$6M
  • MARSHALL WACE, LLP$4M
  • CANADA PENSION PLAN INVESTMENT BOARD$2M
  • BOOTHBAY FUND MANAGEMENT, LLC$1M
  • TUDOR INVESTMENT CORP ET AL$1M

Largest adds

  • Clearline Capital LP$7M
  • Triad Investment Management$6M
  • ALLIANCEBERNSTEIN L.P.$2M
  • BANK OF AMERICA CORP /DE/$2M
  • HRT FINANCIAL LP$2M
  • DIMENSIONAL FUND ADVISORS LP$2M

Largest trims

  • WHITE MOUNTAINS INSURANCE GROUP LTD$65M
  • BlackRock, Inc.$14M
  • Divisadero Street Capital Management, LP$10M
  • MILLENNIUM MANAGEMENT LLC$9M
  • VICTORY CAPITAL MANAGEMENT INC$9M
  • RENAISSANCE TECHNOLOGIES LLC$7M

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).

FundSharesReported value% of valueQuarter
WHITE MOUNTAINS INSURANCE GROUP LTD17,856,614$166M30.0%2026-Q1
BlackRock, Inc. trimmed3,476,687$32M5.8%2026-Q1
Clearline Capital LP added2,590,670$24M4.4%2026-Q1
JPMORGAN CHASE & CO added1,745,679$16M3.0%2026-Q1
VANGUARD CAPITAL MANAGEMENT LLC new1,385,729$13M2.3%2026-Q1
J. Goldman & Co LP added1,182,673$11M2.0%2026-Q1
GEODE CAPITAL MANAGEMENT, LLC added1,070,084$10M1.8%2026-Q1
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added1,061,981$10M1.8%2026-Q1
Triad Investment Management added944,973$9M1.7%2026-Q1
JACOBS ASSET MANAGEMENT, LLC added924,443$9M1.6%2026-Q1
Pacer Advisors, Inc. added411,340$8M1.4%2026-Q1
ACADIAN ASSET MANAGEMENT LLC added847,199$8M1.4%2026-Q1
STATE STREET CORP added838,161$8M1.4%2026-Q1
Shay Capital LLC added775,000$7M1.3%2026-Q1
JACOBS LEVY EQUITY MANAGEMENT, INC added750,054$7M1.3%2026-Q1
RENAISSANCE TECHNOLOGIES LLC trimmed719,300$7M1.2%2026-Q1
MORGAN STANLEY trimmed703,018$7M1.2%2026-Q1
Nuveen, LLC added701,399$7M1.2%2026-Q1
GOLDMAN SACHS GROUP INC trimmed623,421$6M1.0%2026-Q1
DIMENSIONAL FUND ADVISORS LP added620,669$6M1.0%2026-Q1
VANGUARD PORTFOLIO MANAGEMENT LLC new546,745$5M0.9%2026-Q1
SPEECE THORSON CAPITAL GROUP INC new499,011$5M0.8%2026-Q1
Philadelphia Financial Management of San Francisco, LLC added480,000$4M0.8%2026-Q1
AQR CAPITAL MANAGEMENT LLC trimmed467,413$4M0.8%2026-Q1
Qube Research & Technologies Ltd added415,280$4M0.7%2026-Q1
FRANKLIN RESOURCES INC added343,709$3M0.6%2026-Q1
D. E. Shaw & Co., Inc. trimmed342,058$3M0.6%2026-Q1
HRT FINANCIAL LP added329,332$3M0.6%2026-Q1
ALLIANCEBERNSTEIN L.P. added205,440$3M0.5%2026-Q1
JANE STREET GROUP, LLC trimmed283,008$3M0.5%2026-Q1
BANK OF AMERICA CORP /DE/ added279,704$3M0.5%2026-Q1
CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed274,339$3M0.5%2026-Q1
NORTHERN TRUST CORP added271,824$3M0.5%2026-Q1
CITADEL ADVISORS LLC added229,323$2M0.4%2026-Q1
VANGUARD FIDUCIARY TRUST CO new227,112$2M0.4%2026-Q1
PARADIGM ASSET MANAGEMENT CO LLC139,900$2M0.4%2026-Q1
Stoic Point Capital Management LLC added221,041$2M0.4%2026-Q1
Squarepoint Ops LLC added215,541$2M0.4%2026-Q1
SUSQUEHANNA INTERNATIONAL GROUP, LLP added189,736$2M0.3%2026-Q1
TEACHER RETIREMENT SYSTEM OF TEXAS added185,325$2M0.3%2026-Q1
UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added180,511$2M0.3%2026-Q1
TWO SIGMA INVESTMENTS, LP added175,289$2M0.3%2026-Q1
Y-Intercept (Hong Kong) Ltd trimmed158,170$1M0.3%2026-Q1
UBS Group AG added153,883$1M0.3%2026-Q1
Caption Management, LLC added149,048$1M0.3%2026-Q1
XTX Topco Ltd added146,838$1M0.2%2026-Q1
PRINCIPAL FINANCIAL GROUP INC added137,613$1M0.2%2026-Q1
Man Group plc added136,707$1M0.2%2026-Q1
GSA CAPITAL PARTNERS LLP added109,268$1M0.2%2026-Q1
BALYASNY ASSET MANAGEMENT L.P. trimmed108,808$1M0.2%2026-Q1
Quantinno Capital Management LP added107,274$998K0.2%2026-Q1
STATE OF WISCONSIN INVESTMENT BOARD added106,160$987K0.2%2026-Q1
PDT Partners, LLC trimmed90,022$837K0.2%2026-Q1
VICTORY CAPITAL MANAGEMENT INC trimmed87,269$812K0.1%2026-Q1
Bank of New York Mellon Corp trimmed86,955$809K0.1%2026-Q1
Divisadero Street Capital Management, LP trimmed86,907$808K0.1%2026-Q1
Russell Investments Group, Ltd. trimmed84,894$794K0.1%2026-Q1
ALGERT GLOBAL LLC trimmed84,510$786K0.1%2026-Q1
GLOBEFLEX CAPITAL L P80,233$746K0.1%2026-Q1
Amundi added78,104$726K0.1%2026-Q1
Allianz Asset Management GmbH70,176$653K0.1%2026-Q1
Swiss National Bank58,700$546K0.1%2026-Q1
Mariner, LLC trimmed58,489$544K0.1%2026-Q1
BNP PARIBAS FINANCIAL MARKETS trimmed56,206$523K0.1%2026-Q1
BLAIR WILLIAM & CO/IL trimmed55,975$521K0.1%2026-Q1
RHUMBLINE ADVISERS trimmed47,884$445K0.1%2026-Q1
MILLENNIUM MANAGEMENT LLC trimmed47,041$437K0.1%2026-Q1
Allspring Global Investments Holdings, LLC added47,885$435K0.1%2026-Q1
BARCLAYS PLC trimmed45,364$422K0.1%2026-Q1
Dynamic Technology Lab Private Ltd added43,595$405K0.1%2026-Q1
State of Wyoming added43,001$400K0.1%2026-Q1
Brooklyn Investment Group added39,724$369K0.1%2026-Q1
Vanguard Global Advisers, LLC new37,688$350K0.1%2026-Q1
VANGUARD GROUP INC trimmed2,306,750$30M5.4%2025-Q4 stale
Broad Bay Capital Management, LP trimmed1,468,695$17M3.0%2025-Q3 stale
TimesSquare Capital Management, LLC trimmed1,372,174$13M2.3%2025-Q1 stale
G2 Investment Partners Management LLC added496,916$6M1.2%2025-Q4 stale
MARSHALL WACE, LLP added328,388$4M0.8%2025-Q4 stale
Hillsdale Investment Management Inc. added359,200$4M0.7%2025-Q2 stale
LAZARD ASSET MANAGEMENT LLC trimmed294,796$3M0.6%2025-Q3 stale
EARNEST PARTNERS LLC269,607$3M0.6%2025-Q3 stale
Jackson Creek Investment Advisors LLC added164,060$2M0.3%2025-Q2 stale
CANADA PENSION PLAN INVESTMENT BOARD added136,500$2M0.3%2025-Q4 stale
BOOTHBAY FUND MANAGEMENT, LLC added108,143$1M0.3%2025-Q4 stale
Trexquant Investment LP added120,775$1M0.2%2025-Q2 stale
TUDOR INVESTMENT CORP ET AL added83,330$1M0.2%2025-Q4 stale
NOMURA HOLDINGS INC added82,313$1M0.2%2025-Q4 stale
Lighthouse Investment Partners, LLC trimmed82,050$1M0.2%2025-Q4 stale
ExodusPoint Capital Management, LP trimmed81,791$1M0.2%2025-Q4 stale
Janney Montgomery Scott LLC trimmed70,355$801K0.1%2025-Q3 stale
RAYMOND JAMES FINANCIAL INC added52,708$683K0.1%2025-Q4 stale
HSBC HOLDINGS PLC added51,550$561K0.1%2025-Q2 stale
Verition Fund Management LLC trimmed39,303$509K0.1%2025-Q4 stale
Semanteon Capital Management, LP added44,583$507K0.1%2025-Q3 stale
Gotham Asset Management, LLC trimmed39,123$507K0.1%2025-Q4 stale
AlphaQuest LLC added37,463$485K0.1%2025-Q4 stale
Thrivent Financial for Lutherans added36,379$471K0.1%2025-Q4 stale
PharVision Advisers, LLC added34,034$441K0.1%2025-Q4 stale
Versor Investments LP new29,318$380K0.1%2025-Q4 stale
Jain Global LLC added31,143$354K0.1%2025-Q3 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.

HoldersTotal shares

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.

Learn how to read institutional ownership