Who owns MDEX (MDEX)
Which tracked institutional funds hold MDEX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MDEX company fundamentals →
Ownership as of the 2026-Q1 13F filings. 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
2 tracked funds added or opened MDEX while 4 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
MDEX’s largest tracked holder by dollar value, Madison Asset Management, LLC, sizes it at 0.6% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.6pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in MDEX 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 7 tracked filers holding MDEX, 4 increased or opened the position and 8 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
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 MDEX 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 1
- ZEGA Investments, LLC$2M
Full exits 3
- Tidal Investments LLC$4M
- JANE STREET GROUP, LLC$731K
- CITADEL ADVISORS LLC$562K
Largest adds
- ROYAL BANK OF CANADA$2M
Largest trims
- Madison Asset Management, LLC$6M
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).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| Madison Asset Management, LLC trimmed | 2,510,249 | $51M | 88.3% | 2026-Q1 |
| ZEGA Investments, LLC new | 62,990 | $1M | 2.2% | 2026-Q1 |
| Centric Wealth Management added | 51,599 | $1M | 1.8% | 2026-Q1 |
| GTS SECURITIES LLC added | 16,340 | $399K | 0.7% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 11,272 | $275K | 0.5% | 2026-Q1 |
| ROYAL BANK OF CANADA | 7,317 | $149K | 0.3% | 2026-Q1 |
| UBS Group AG trimmed | 248 | $6K | 0.0% | 2026-Q1 |
| Tidal Investments LLC trimmed | 102,049 | $2M | 3.6% | 2025-Q4 stale |
| JANE STREET GROUP, LLC added | 35,631 | $731K | 1.3% | 2025-Q4 stale |
| CITADEL ADVISORS LLC added | 24,542 | $562K | 1.0% | 2025-Q4 stale |
| Focus Partners Wealth new | 11,269 | $247K | 0.4% | 2025-Q1 stale |
| FMR LLC new | 1 | $21 | 0.0% | 2025-Q4 stale |
| Front Row Advisors LLC trimmed | 120 | $1 | 0.0% | 2025-Q4 stale |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | 0 | — | 0.0% | 2025-Q2 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.
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.