Who owns Magnolia Oil & Gas (MGY)
Which tracked institutional funds hold MGY, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MGY 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
The tracked-fund tape on MGY is one-sided between 2026-Q1 and 2026-Q2: 44 added or opened and 165 trimmed or exited — on balance reducing.
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
MGY’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes MGY more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in MGY 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 381 tracked filers holding MGY, 210 increased or opened the position and 205 reduced or closed it; over the same quarter, open-market insider Form 4s were net purchases.
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 MGY 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 19
- Jupiter Topco LLC$164M
- Conestoga Capital Advisors, LLC$24M
- FORT WASHINGTON INVESTMENT ADVISORS INC /OH/$22M
- MARSHALL WACE, LLP$8M
- Aventail Capital Group, LP$5M
- LAZARD ASSET MANAGEMENT LLC$4M
Full exits 34
- JANUS HENDERSON GROUP PLC$198M
- T. Rowe Price Investment Management, Inc.$164M
- GW&K Investment Management, LLC$97M
- BESSEMER GROUP INC$40M
- Corigliano Investment Advisers, LLC$13M
- CITADEL ADVISORS LLC$11M
Largest adds
- PRICE T ROWE ASSOCIATES INC /MD/$36M
- ALLIANCEBERNSTEIN L.P.$33M
- WESTWOOD HOLDINGS GROUP INC$17M
- FEDERATED HERMES, INC.$5M
- Trexquant Investment LP$3M
- Creative Planning$3M
Largest trims
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$58M
- TD Asset Management Inc$55M
- AMERICAN CENTURY COMPANIES INC$50M
- NOMURA ASSET MANAGEMENT INTERNATIONAL INC.$47M
- STATE STREET CORP$45M
- Epoch Investment Partners, Inc.$44M
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 |
|---|---|---|---|---|
| BlackRock, Inc. added | 31,972,219 | $818M | 16.9% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 15,341,201 | $392M | 8.1% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC added | 11,011,458 | $282M | 5.8% | 2026-Q2 |
| STATE STREET CORP added | 9,941,466 | $254M | 5.3% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 7,663,263 | $196M | 4.1% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 7,117,449 | $182M | 3.8% | 2026-Q2 |
| Jupiter Topco LLC new | 6,427,893 | $164M | 3.4% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 5,463,526 | $140M | 2.9% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 4,802,973 | $123M | 2.5% | 2026-Q2 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. trimmed | 4,311,973 | $110M | 2.3% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ added | 4,253,346 | $109M | 2.3% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. trimmed | 4,122,434 | $130M | 2.7% | 2026-Q2 |
| TD Asset Management Inc trimmed | 3,934,160 | $101M | 2.1% | 2026-Q2 |
| Epoch Investment Partners, Inc. trimmed | 3,569,975 | $91M | 1.9% | 2026-Q2 |
| MORGAN STANLEY added | 3,429,471 | $88M | 1.8% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 2,982,883 | $76M | 1.6% | 2026-Q2 |
| SYSTEMATIC FINANCIAL MANAGEMENT LP trimmed | 2,777,352 | $71M | 1.5% | 2026-Q2 |
| Allspring Global Investments Holdings, LLC trimmed | 2,667,136 | $67M | 1.4% | 2026-Q2 |
| WESTWOOD HOLDINGS GROUP INC added | 2,642,440 | $68M | 1.4% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 2,618,204 | $67M | 1.4% | 2026-Q2 |
| SILVERCREST ASSET MANAGEMENT GROUP LLC trimmed | 2,537,333 | $65M | 1.3% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 2,406,168 | $62M | 1.3% | 2026-Q2 |
| Boston Trust Walden Corp trimmed | 2,384,760 | $61M | 1.3% | 2026-Q2 |
| Nuveen, LLC trimmed | 2,228,804 | $57M | 1.2% | 2026-Q2 |
| Stephens Investment Management Group LLC added | 2,219,966 | $57M | 1.2% | 2026-Q2 |
| LOOMIS SAYLES & CO L P trimmed | 2,065,051 | $53M | 1.1% | 2026-Q2 |
| Bank of New York Mellon Corp added | 1,944,363 | $50M | 1.0% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 1,894,970 | $48M | 1.0% | 2026-Q2 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE added | 1,857,192 | $48M | 1.0% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 1,713,122 | $44M | 0.9% | 2026-Q2 |
| UBS Group AG added | 1,503,941 | $38M | 0.8% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP trimmed | 1,416,670 | $36M | 0.8% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 1,330,499 | $34M | 0.7% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 1,296,902 | $33M | 0.7% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC trimmed | 1,120,762 | $29M | 0.6% | 2026-Q2 |
| Aberdeen Group plc added | 958,945 | $25M | 0.5% | 2026-Q2 |
| Conestoga Capital Advisors, LLC new | 935,605 | $24M | 0.5% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 926,677 | $24M | 0.5% | 2026-Q2 |
| FORT WASHINGTON INVESTMENT ADVISORS INC /OH/ new | 870,898 | $22M | 0.5% | 2026-Q2 |
| FIRST TRUST ADVISORS LP trimmed | 830,702 | $21M | 0.4% | 2026-Q2 |
| Public Sector Pension Investment Board trimmed | 793,479 | $20M | 0.4% | 2026-Q2 |
| Invesco Ltd. added | 742,620 | $19M | 0.4% | 2026-Q2 |
| Creative Planning added | 633,423 | $16M | 0.3% | 2026-Q2 |
| HEARTLAND ADVISORS INC trimmed | 615,475 | $16M | 0.3% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 594,648 | $15M | 0.3% | 2026-Q2 |
| ALGERT GLOBAL LLC added | 551,900 | $14M | 0.3% | 2026-Q2 |
| RHUMBLINE ADVISERS trimmed | 524,565 | $13M | 0.3% | 2026-Q2 |
| BARROW HANLEY MEWHINNEY & STRAUSS LLC added | 515,963 | $13M | 0.3% | 2026-Q2 |
| GILDER GAGNON HOWE & CO LLC trimmed | 480,127 | $12M | 0.3% | 2026-Q2 |
| Edgestream Partners, L.P. added | 478,721 | $12M | 0.3% | 2026-Q2 |
| Diamond Hill Capital Management, LLC (Investment Advisor) added | 468,704 | $12M | 0.2% | 2026-Q2 |
| California Public Employees Retirement System added | 456,471 | $12M | 0.2% | 2026-Q2 |
| OBERWEIS ASSET MANAGEMENT INC/ added | 456,466 | $12M | 0.2% | 2026-Q2 |
| ENVESTNET ASSET MANAGEMENT INC added | 434,943 | $11M | 0.2% | 2026-Q2 |
| Squarepoint Ops LLC trimmed | 430,380 | $11M | 0.2% | 2026-Q2 |
| Trexquant Investment LP added | 422,732 | $11M | 0.2% | 2026-Q2 |
| Legal & General Group Plc added | 389,923 | $10M | 0.2% | 2026-Q2 |
| Point72 Asset Management, L.P. trimmed | 385,561 | $10M | 0.2% | 2026-Q2 |
| NORDEA INVESTMENT MANAGEMENT AB added | 367,290 | $10M | 0.2% | 2026-Q2 |
| Swiss National Bank added | 363,300 | $9M | 0.2% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 359,835 | $9M | 0.2% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 353,570 | $9M | 0.2% | 2026-Q2 |
| MARSHALL WACE, LLP added | 328,279 | $8M | 0.2% | 2026-Q2 |
| Clark Capital Management Group, Inc. added | 320,995 | $8M | 0.2% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 311,090 | $8M | 0.2% | 2026-Q2 |
| Universal- Beteiligungs- und Servicegesellschaft mbH added | 286,035 | $7M | 0.2% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC trimmed | 281,030 | $7M | 0.1% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 273,602 | $7M | 0.1% | 2026-Q2 |
| Foster Victor Wealth Advisors, LLC trimmed | 265,272 | $7M | 0.1% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 261,428 | $7M | 0.1% | 2026-Q2 |
| KING LUTHER CAPITAL MANAGEMENT CORP added | 259,018 | $7M | 0.1% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 234,139 | $6M | 0.1% | 2026-Q2 |
| SIR Capital Management, L.P. trimmed | 227,667 | $6M | 0.1% | 2026-Q2 |
| FEDERATED HERMES, INC. added | 216,186 | $6M | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 213,180 | $5M | 0.1% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 208,440 | $5M | 0.1% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 196,729 | $5M | 0.1% | 2026-Q2 |
| PRUDENTIAL FINANCIAL INC trimmed | 191,670 | $5M | 0.1% | 2026-Q2 |
| FRANKLIN RESOURCES INC trimmed | 189,120 | $5M | 0.1% | 2026-Q2 |
| Phocas Financial Corp. trimmed | 187,730 | $5M | 0.1% | 2026-Q2 |
| Aventail Capital Group, LP trimmed | 187,617 | $5M | 0.1% | 2026-Q2 |
| GREAT LAKES ADVISORS, LLC trimmed | 182,784 | $5M | 0.1% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 177,870 | $5M | 0.1% | 2026-Q2 |
| Emerald Investment Advisers, LLC trimmed | 176,541 | $5M | 0.1% | 2026-Q2 |
| FRED ALGER MANAGEMENT, LLC trimmed | 171,139 | $4M | 0.1% | 2026-Q2 |
| BARCLAYS PLC trimmed | 169,430 | $4M | 0.1% | 2026-Q2 |
| Moody Aldrich Partners LLC trimmed | 167,040 | $4M | 0.1% | 2026-Q2 |
| FIFTH THIRD BANCORP added | 165,467 | $4M | 0.1% | 2026-Q2 |
| LAZARD ASSET MANAGEMENT LLC trimmed | 163,263 | $4M | 0.1% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd added | 155,158 | $4M | 0.1% | 2026-Q2 |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC trimmed | 155,059 | $4M | 0.1% | 2026-Q2 |
| Empowered Funds, LLC added | 151,858 | $4M | 0.1% | 2026-Q2 |
| VAN ECK ASSOCIATES CORP new | 149,697 | $4M | 0.1% | 2026-Q2 |
| Cerity Partners LLC added | 142,648 | $4M | 0.1% | 2026-Q2 |
| Rafferty Asset Management, LLC trimmed | 141,860 | $4M | 0.1% | 2026-Q2 |
| ROYAL BANK OF CANADA added | 139,992 | $4M | 0.1% | 2026-Q2 |
| Pathstone Holdings, LLC trimmed | 130,193 | $3M | 0.1% | 2026-Q2 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM trimmed | 123,730 | $3M | 0.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. trimmed | 122,150 | $3M | 0.1% | 2026-Q2 |
| PUBLIC EMPLOYEES RETIREMENT SYSTEM OF OHIO added | 120,293 | $3M | 0.1% | 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.