% of shares outstanding is not shown for RKLX: this is a fund line, and we hold no cover-page share count for it at any quarter — a fund's shares outstanding move with creations and redemptions rather than with issuance and buybacks, and it is not the SEC cover-page count this percentage is defined against. The figure is withheld rather than computed against a count that does not exist. Holder share counts are shown as filed.
Crowding percentile withheld — no market cap for RKLX 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 | BANK OF AMERICA CORP /DE/ | 59,48759,487 | $2M | — | NEW |
| 2 | Optiver Holding B.V. | 26,36426,364 | $674,127 | — | ADD 100% |
| 3 | Jump Financial, LLC | 26,02526,025 | $665,459 | — | NEW |
| 4 | IMC-Chicago, LLC | 18,53518,535 | $473,940 | — | NEW |
| 5 | StoneX Group Inc. | 15,66815,668 | $400,631 | — | TRIM -4% |
| 6 | HRT FINANCIAL LP | 8,7318,731 | $223,000 | — | NEW |
| 7 | Belvedere Trading LLC | 3,5523,552 | $90,825 | — | NEW |
| 8 | MORGAN STANLEY | 1010 | $256 | — | TRIM -47% |
| 9 | UBS Group AG | 11 | $26 | — | TRIM -100% |
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 |
|---|---|---|---|---|---|---|---|
| BANK OF AMERICA CORP /DE/ | — | — | — | — | — | 59K | $2M |
| Optiver Holding B.V. | — | — | 11K | — | 13K | 26K | $674,127 |
| Jump Financial, LLC | — | — | — | — | — | 26K | $665,459 |
| IMC-Chicago, LLC | — | — | — | — | — | 19K | $473,940 |
| StoneX Group Inc. | — | — | — | — | 16K | 16K | $400,631 |
| HRT FINANCIAL LP | — | — | — | — | — | 9K | $223,000 |
| Belvedere Trading LLC | — | — | — | 3K | — | 4K | $90,825 |
| MORGAN STANLEY | — | — | — | — | 19 | 10 | $256 |
| UBS Group AG | — | — | 7K | 55K | 168K | 1 | $26 |
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.
| Quarter | Holders | Shares held | % shares out | Value held |
|---|---|---|---|---|
| 2026-Q1 | 9 | 158,373 | — | $4M |
| 2025-Q4 | 9 | 223,945 | — | $9M |
| 2025-Q3 | 2 | 57,829 | — | $5M |
| 2025-Q2 | 3 | 30,782 | — | $2M |
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 | |
|---|---|---|---|
| BANK OF AMERICA CORP /DE/ | +59,487 | $2M | OPEN |
| Jump Financial, LLC | +26,025 | $665,459 | OPEN |
| IMC-Chicago, LLC | +18,535 | $473,940 | OPEN |
| Optiver Holding B.V. | +13,189 | $337,243 | ADD |
| HRT FINANCIAL LP | +8,731 | $223,252 | OPEN |
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| UBS Group AG | −167,815 | $4M | TRIM |
| CITADEL ADVISORS LLC | −22,912 | $585,860 | CLOSE |
| GROUP ONE TRADING LLC | −1,833 | $46,870 | CLOSE |
| SIMPLEX TRADING, LLC | −997 | $25,493 | CLOSE |
| StoneX Group Inc. | −706 | $18,052 | TRIM |
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).
