% of shares outstanding not shown: no SEC cover-page share count falls within 120 days of the 2026-Q1 quarter end, so any percentage would rest on a count that cannot speak for this quarter. Holder share counts are shown as filed.
Crowding percentile withheld — no market cap for MRDN in the served universe — the cohort is size-matched, and an unmatched percentile would compare a micro-cap register to a mega-cap one.
Rows rank by the value each filer reported — 13F filers price their own positions, so a holder with fewer shares can rank just above one with more.
| Holder | 2024-Q4 | 2025-Q1 | 2025-Q2 | 2025-Q3 | 2025-Q4 | 2026-Q1 | Latest value |
|---|---|---|---|---|---|---|---|
| Topline Capital Management, LLC | — | — | — | — | — | 140K | $1M |
| BlackRock, Inc. | — | — | — | — | — | 95K | $687,655 |
| GEODE CAPITAL MANAGEMENT, LLC | — | — | — | — | — | 71K | $510,988 |
| Whetstone Capital Advisors, LLC | — | — | — | — | — | 63K | $457,163 |
| VANGUARD CAPITAL MANAGEMENT LLC | — | — | — | — | — | 26K | $189,908 |
| VANGUARD FIDUCIARY TRUST CO | — | — | — | — | — | 15K | $110,719 |
| UBS Group AG | — | — | — | — | — | 14K | $104,452 |
| NORTHERN TRUST CORP | — | — | — | — | — | 14K | $102,155 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | — | — | — | — | — | 11K | $80,821 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | — | — | — | — | — | 10K | $75,269 |
| STATE STREET CORP | — | — | — | — | — | 10K | $72,395 |
| DEUTSCHE BANK AG\ | — | — | — | — | — | 8K | $56,973 |
| FMR LLC | — | — | — | — | — | 6K | $42,454 |
| LOS ANGELES CAPITAL MANAGEMENT LLC | — | — | — | — | — | 4K | $32,165 |
| MORGAN STANLEY | — | — | — | — | — | 4K | $31,776 |
Shares reported each quarter by the largest current holders. Green = added vs the prior filing, red = trimmed, grey = roughly held; a dash is a quarter with no 13F on file (a gap is skipped, not read as an exit). 13F is filed up to 45 days after quarter-end. Up to 40 quarters (10 years) available — use the selector above.
Short interest has its own tab now — open SI →
Source: SEC Form 13F — every institution manager (≥ $100M in 13F securities) reporting a long US-listed position, across ~10,250 filers over 10 years of history. 13F is long-only, US-listed, filed up to 45 days after quarter-end.
| Biggest buyers | Δ shares | Δ value | |
|---|---|---|---|
| Topline Capital Management, LLC | +140,266 | — | OPEN |
| BlackRock, Inc. | +95,243 | — | OPEN |
| GEODE CAPITAL MANAGEMENT, LLC | +70,766 | — | OPEN |
| Whetstone Capital Advisors, LLC | +63,319 | — | OPEN |
| VANGUARD CAPITAL MANAGEMENT LLC | +26,303 | — | OPEN |
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| No filer reduced its position this quarter. | |||
The 2025-Q4 register is as-filed in ITS OWN share basis; every count below was rebased into the 2026-Q1 basis (no split in between, factor 1). Dollar figures value the SHARE delta at one price — the quarter-end close — rather than differencing two filings' own reported values, which would mix the quarter's price move into the trade figure. No licensed quarter-end close is stored for this line, so the dollar columns are withheld; share counts stand.
13Fs disclose LONG US-listed positions only — shorts, most derivatives, bonds and non-US listings are invisible here, and a filer's quarter-over-quarter change is not necessarily a trade (index rebalances, in-kind transfers and entity successions all read as flow).
