Who owns Mesa Laboratories (MLAB)
Which tracked institutional funds hold MLAB, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MLAB 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 MLAB is one-sided between 2026-Q1 and 2026-Q2: 52 added or opened and 14 trimmed or exited — on balance accumulating.
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
MLAB’s largest tracked holder by dollar value, Long Path Partners LP, sizes it at 20.2% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 20.2pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in MLAB 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 154 tracked filers holding MLAB, 92 increased or opened the position and 65 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 MLAB 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 6
- JANE STREET GROUP, LLC$7M
- Qube Research & Technologies Ltd$4M
- Jupiter Topco LLC$3M
- NFJ INVESTMENT GROUP, LLC$1M
- MARSHALL WACE, LLP$870K
- CM WEALTH ADVISORS LLC$830K
Full exits 9
- Select Equity Group, L.P.$21M
- Roubaix Capital, LLC$6M
- JANUS HENDERSON GROUP PLC$6M
- LAZARD ASSET MANAGEMENT LLC$2M
- Trexquant Investment LP$2M
- PUBLIC EMPLOYEES RETIREMENT SYSTEM OF OHIO$1M
Largest adds
- Long Path Partners LP$12M
- JACOBS LEVY EQUITY MANAGEMENT, INC$9M
- BlackRock, Inc.$9M
- FMR LLC$8M
- WASATCH ADVISORS LP$7M
- AQR CAPITAL MANAGEMENT LLC$5M
Largest trims
- MONIMUS CAPITAL MANAGEMENT, LP$3M
- ROYCE & ASSOCIATES LP$3M
- Ranger Investment Management, L.P.$620K
- CenterBook Partners LP$485K
- UBS Group AG$291K
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 |
|---|---|---|---|---|
| Long Path Partners LP added | 477,126 | $47M | 9.5% | 2026-Q2 |
| BlackRock, Inc. added | 440,552 | $44M | 8.8% | 2026-Q2 |
| Boston Partners trimmed | 265,149 | $26M | 5.3% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 237,457 | $24M | 4.7% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 203,739 | $20M | 4.1% | 2026-Q2 |
| Ranger Investment Management, L.P. trimmed | 173,988 | $17M | 3.5% | 2026-Q2 |
| MORGAN STANLEY trimmed | 156,979 | $16M | 3.1% | 2026-Q2 |
| Diamond Hill Capital Management, LLC (Investment Advisor) added | 155,771 | $16M | 3.1% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC added | 149,937 | $15M | 3.0% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 148,395 | $15M | 3.0% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 139,682 | $14M | 2.8% | 2026-Q2 |
| KENNEDY CAPITAL MANAGEMENT LLC trimmed | 138,301 | $14M | 2.8% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 130,838 | $13M | 2.6% | 2026-Q2 |
| STATE STREET CORP added | 124,292 | $12M | 2.5% | 2026-Q2 |
| Russell Investments Group, Ltd. trimmed | 121,845 | $12M | 2.4% | 2026-Q2 |
| WASATCH ADVISORS LP added | 115,668 | $12M | 2.3% | 2026-Q2 |
| ROYCE & ASSOCIATES LP trimmed | 113,395 | $11M | 2.3% | 2026-Q2 |
| CRAWFORD INVESTMENT COUNSEL INC added | 98,805 | $10M | 2.0% | 2026-Q2 |
| FMR LLC added | 88,857 | $9M | 1.8% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 81,755 | $8M | 1.6% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 71,580 | $7M | 1.4% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 69,350 | $7M | 1.4% | 2026-Q2 |
| Meros Investment Management, LP trimmed | 67,962 | $7M | 1.4% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 65,745 | $7M | 1.3% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 64,322 | $6M | 1.3% | 2026-Q2 |
| GABELLI FUNDS LLC | 62,499 | $6M | 1.2% | 2026-Q2 |
| MONIMUS CAPITAL MANAGEMENT, LP trimmed | 55,344 | $6M | 1.1% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 54,463 | $5M | 1.1% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 49,952 | $5M | 1.0% | 2026-Q2 |
| Bank of New York Mellon Corp added | 45,602 | $5M | 0.9% | 2026-Q2 |
| HERALD INVESTMENT MANAGEMENT Ltd trimmed | 42,500 | $4M | 0.8% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 39,536 | $4M | 0.8% | 2026-Q2 |
| Qube Research & Technologies Ltd added | 37,402 | $4M | 0.7% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 35,890 | $4M | 0.7% | 2026-Q2 |
| Jupiter Topco LLC new | 30,996 | $3M | 0.6% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 29,239 | $3M | 0.6% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 28,900 | $3M | 0.6% | 2026-Q2 |
| BBR PARTNERS, LLC | 25,195 | $3M | 0.5% | 2026-Q2 |
| Man Group plc added | 24,070 | $2M | 0.5% | 2026-Q2 |
| Point72 Asset Management, L.P. added | 22,514 | $2M | 0.4% | 2026-Q2 |
| FRANKLIN RESOURCES INC added | 21,905 | $2M | 0.4% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC added | 20,364 | $2M | 0.4% | 2026-Q2 |
| RICE HALL JAMES & ASSOCIATES, LLC added | 18,968 | $2M | 0.4% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 18,906 | $2M | 0.4% | 2026-Q2 |
| SEGALL BRYANT & HAMILL, LLC trimmed | 18,108 | $2M | 0.4% | 2026-Q2 |
| Numerai GP LLC added | 17,769 | $2M | 0.4% | 2026-Q2 |
| XTX Topco Ltd added | 17,475 | $2M | 0.3% | 2026-Q2 |
| KING LUTHER CAPITAL MANAGEMENT CORP | 17,411 | $2M | 0.3% | 2026-Q2 |
| Creative Planning added | 16,615 | $2M | 0.3% | 2026-Q2 |
| ROYAL BANK OF CANADA added | 14,803 | $1M | 0.3% | 2026-Q2 |
| Engineers Gate Manager LP added | 14,731 | $1M | 0.3% | 2026-Q2 |
| Mariner, LLC added | 14,407 | $1M | 0.3% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 14,386 | $1M | 0.3% | 2026-Q2 |
| NFJ INVESTMENT GROUP, LLC new | 14,256 | $1M | 0.3% | 2026-Q2 |
| Nuveen, LLC added | 13,896 | $1M | 0.3% | 2026-Q2 |
| IEQ CAPITAL, LLC added | 13,580 | $1M | 0.3% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC added | 12,069 | $1M | 0.2% | 2026-Q2 |
| Invesco Ltd. trimmed | 11,862 | $1M | 0.2% | 2026-Q2 |
| GLOBEFLEX CAPITAL L P added | 11,581 | $1M | 0.2% | 2026-Q2 |
| STIFEL FINANCIAL CORP trimmed | 11,202 | $1M | 0.2% | 2026-Q2 |
| Y-Intercept (Hong Kong) Ltd added | 10,010 | $996K | 0.2% | 2026-Q2 |
| ENVESTNET ASSET MANAGEMENT INC added | 8,816 | $878K | 0.2% | 2026-Q2 |
| MARSHALL WACE, LLP added | 8,740 | $870K | 0.2% | 2026-Q2 |
| CM WEALTH ADVISORS LLC new | 8,341 | $830K | 0.2% | 2026-Q2 |
| GAMCO INVESTORS, INC. ET AL added | 8,340 | $830K | 0.2% | 2026-Q2 |
| UBS Group AG trimmed | 7,773 | $774K | 0.2% | 2026-Q2 |
| CenterBook Partners LP trimmed | 7,739 | $770K | 0.2% | 2026-Q2 |
| Quadrature Capital Ltd trimmed | 7,682 | $765K | 0.2% | 2026-Q2 |
| Vident Advisory, LLC | 7,608 | $757K | 0.2% | 2026-Q2 |
| Cerity Partners LLC added | 7,413 | $738K | 0.1% | 2026-Q2 |
| LOS ANGELES CAPITAL MANAGEMENT LLC added | 7,388 | $735K | 0.1% | 2026-Q2 |
| Quantinno Capital Management LP added | 7,067 | $704K | 0.1% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 6,759 | $673K | 0.1% | 2026-Q2 |
| MERCER GLOBAL ADVISORS INC /ADV added | 6,756 | $673K | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 6,560 | $653K | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 6,500 | $575K | 0.1% | 2026-Q2 |
| CANADA PENSION PLAN INVESTMENT BOARD trimmed | 6,300 | $627K | 0.1% | 2026-Q2 |
| LPL Financial LLC added | 6,044 | $602K | 0.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 5,607 | $558K | 0.1% | 2026-Q2 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM added | 5,445 | $542K | 0.1% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 5,380 | $536K | 0.1% | 2026-Q2 |
| Brevan Howard Capital Management LP trimmed | 4,489 | $447K | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 4,393 | $438K | 0.1% | 2026-Q2 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC added | 4,275 | $409K | 0.1% | 2026-Q2 |
| Magnetar Financial LLC new | 4,139 | $412K | 0.1% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 3,949 | $393K | 0.1% | 2026-Q2 |
| STRS OHIO new | 3,700 | $368K | 0.1% | 2026-Q2 |
| SEIZERT CAPITAL PARTNERS, LLC new | 3,446 | $343K | 0.1% | 2026-Q2 |
| CAPTRUST FINANCIAL ADVISORS added | 3,273 | $326K | 0.1% | 2026-Q2 |
| PRELUDE CAPITAL MANAGEMENT, LLC new | 3,141 | $313K | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC added | 3,094 | $308K | 0.1% | 2026-Q2 |
| Dynamic Technology Lab Private Ltd trimmed | 2,921 | $291K | 0.1% | 2026-Q2 |
| Graham Capital Management, L.P. trimmed | 2,859 | $285K | 0.1% | 2026-Q2 |
| Integrated Quantitative Investments LLC new | 2,590 | $258K | 0.1% | 2026-Q2 |
| CITIGROUP INC added | 2,510 | $250K | 0.1% | 2026-Q2 |
| Kings Path Partners LLC trimmed | 2,433 | $242K | 0.0% | 2026-Q2 |
| Corient Private Wealth LP new | 2,423 | $241K | 0.0% | 2026-Q2 |
| Topline Capital Management, LLC new | 2,374 | $236K | 0.0% | 2026-Q2 |
| Baird Financial Group, Inc. new | 2,325 | $231K | 0.0% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND | 2,143 | $213K | 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.