% 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 ZLNDY in the served universe — the cohort is size-matched, and an unmatched percentile would compare a micro-cap register to a mega-cap one.
| # | Holder | Shares | Value | % of shares out | Δ QoQ |
|---|---|---|---|---|---|
| 1 | RHUMBLINE ADVISERS | 9,7259,725 | $117,579 | — | — |
| 2 | Salomon & Ludwin, LLC | 7070 | $847 | — | TRIM -72% |
| 3 | GAMMA Investing LLC | 2020 | $242 | — | — |
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 |
|---|---|---|---|---|---|---|---|
| RHUMBLINE ADVISERS | 4K | 8K | 8K | 8K | 10K | 10K | $117,579 |
| Salomon & Ludwin, LLC | — | — | 7 | 180 | 246 | 70 | $847 |
| GAMMA Investing LLC | 20 | 20 | 20 | 20 | 20 | 20 | $242 |
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.
Holder count only — too few computable %-of-shares-outstanding quarters for a % pane. Line breaks are quarters with no 13F record, never interpolated.
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 | |
|---|---|---|---|
| No filer increased its position this quarter. | |||
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| Salomon & Ludwin, LLC | −176 | $2,128 | TRIM |
| Signature Equity Partners, LLC | −55 | $665 | CLOSE |
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 2026-03-31 close — rather than differencing two filings' own reported values, which would mix the quarter's price move into the trade figure.
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).
| Quarter | Holders | Shares held | % shares out | Value held |
|---|---|---|---|---|
| 2026-Q1 | 3 | 9,815 | — | $118,668 |
| 2025-Q4 | 4 | 10,046 | — | $148,179 |
| 2025-Q3 | 3 | 8,380 | — | $128,263 |
| 2025-Q2 | 4 | 8,307 | — | $137,230 |
| 2025-Q1 | 3 | 7,758 | — | $134,048 |
| 2024-Q4 | 2 | 4,317 | — | $73,343 |
| 2024-Q3 | 2 | 4,007 | — | $66,059 |
| 2024-Q2 | 1 | 3,572 | — | $41,540 |
| 2024-Q1 | 1 | 3,702 | — | $52,787 |
| 2023-Q4 | 1 | 2,254 | — | $26,697 |
| 2023-Q3 | 1 | 1,581 | — | $17,469 |
| 2023-Q2 | 1 | 1,581 | — | $22,718 |
| 2023-Q1 | 1 | 12 | — | $250 |
| 2022-Q2 | 1 | 44 | — | $1,000 |
| 2022-Q1 | 1 | 279 | — | $7,000 |
| 2021-Q4 | 1 | 231 | — | $9,000 |
| 2021-Q3 | 1 | 155 | — | $7,000 |
| 2021-Q2 | 2 | 28,001 | — | $2M |
| 2021-Q1 | 3 | 879,312 | — | $43M |
| 2020-Q4 | 2 | 880,892 | — | $49M |
| 2020-Q3 | 2 | 794,322 | — | $37M |
| 2020-Q2 | 2 | 834,556 | — | $30M |
| 2020-Q1 | 2 | 750,375 | — | $14M |
| 2019-Q4 | 4 | 670,666 | — | $17M |
| 2019-Q3 | 3 | 607,754 | — | $14M |
| 2019-Q2 | 4 | 599,245 | — | $13M |
| 2019-Q1 | 5 | 558,321 | — | $11M |
| 2018-Q4 | 3 | 331,633 | — | $4M |
| 2018-Q3 | 1 | 70,061 | — | $1M |
| 2018-Q2 | 2 | 747,213 | — | $21M |
| 2018-Q1 | 2 | 614,981 | — | $17M |
| 2017-Q4 | 2 | 446,482 | — | $12M |
| 2017-Q3 | 2 | 367,170 | — | $9M |
| 2017-Q2 | 2 | 232,005 | — | $5M |
| 2017-Q1 | 2 | 216,604 | — | $4M |
| 2016-Q4 | 2 | 232,678 | — | $4M |
| 2016-Q3 | 4 | 275,652 | — | $6M |
| 2016-Q2 | 3 | 1,882,152 | — | $25M |
| 2016-Q1 | 1 | 202,341 | — | $3M |
| 2015-Q4 | 1 | 105,065 | — | $2M |
