% 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 RUMBW 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 | BOOTHBAY FUND MANAGEMENT, LLC | 424,600424,600 | $2M | — | — |
| 2 | LMR Partners LLP | 1,487,1531.5M | $2M | — | — |
| 3 | CANTOR FITZGERALD, L. P. | 550,000550,000 | $588,500 | — | — |
| 4 | ARISTEIA CAPITAL, L.L.C. | 504,440504,440 | $519,573 | — | — |
| 5 | D. E. Shaw & Co., Inc. | 106,572106,572 | $114,032 | — | — |
| 6 | Hudson Bay Capital Management LP | 58,59358,593 | $62,695 | — | — |
| 7 | Private Advisor Group, LLC | 48,71048,710 | $52,120 | — | TRIM -5% |
| 8 | Creative Planning | 21,50021,500 | $23,005 | — | ADD 87% |
| 9 | Stratos Wealth Partners, LTD. | 16,99516,995 | $18,185 | — | TRIM -26% |
| 10 | WOLVERINE ASSET MANAGEMENT LLC | 1,6141,614 | $1,727 | — | NEW |
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 |
|---|---|---|---|---|---|---|---|
| BOOTHBAY FUND MANAGEMENT, LLC | 203K | 203K | 389K | 389K | 425K | 425K | $2M |
| LMR Partners LLP | 1.4M | 1.5M | 1.5M | 1.5M | 1.5M | 1.5M | $2M |
| CANTOR FITZGERALD, L. P. | 550K | 550K | 550K | 550K | 550K | 550K | $588,500 |
| ARISTEIA CAPITAL, L.L.C. | 151K | 302K | 366K | 492K | 504K | 504K | $519,573 |
| D. E. Shaw & Co., Inc. | 107K | 107K | 107K | 107K | 107K | 107K | $114,032 |
| Hudson Bay Capital Management LP | — | 50K | 50K | 50K | 59K | 59K | $62,695 |
| Private Advisor Group, LLC | 23K | 36K | 34K | 40K | 51K | 49K | $52,120 |
| Creative Planning | — | — | 11K | 12K | 12K | 22K | $23,005 |
| Stratos Wealth Partners, LTD. | 23K | 23K | 23K | 23K | 23K | 17K | $18,185 |
| WOLVERINE ASSET MANAGEMENT LLC | 11K | 6K | 5K | 414 | — | 2K | $1,727 |
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 | 10 | 3,220,177 | — | $5M |
| 2025-Q4 | 11 | 4,352,100 | — | $10M |
| 2025-Q3 | 12 | 4,303,029 | — | $11M |
| 2025-Q2 | 14 |
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 | |
|---|---|---|---|
| Creative Planning | +10,000 | — | ADD |
| WOLVERINE ASSET MANAGEMENT LLC | +1,614 | — | OPEN |
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| ZAZOVE ASSOCIATES LLC | −1,129,943 | — | CLOSE |
| Stratos Wealth Partners, LTD. | −5,850 | — | TRIM |
| LMR Partners LLP | −5,109 | — | — |
| Private Advisor Group, LLC | −2,500 | — | TRIM |
| UBS Group AG | −135 | — | 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 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).
| 4,169,040 |
| — |
| $15M |
| 2025-Q1 | 12 | 3,919,431 | — | $10M |
| 2024-Q4 | 13 | 3,579,845 | — | $20M |
| 2024-Q3 | 9 | 2,021,939 | — | $3M |
| 2024-Q2 | 14 | 4,384,767 | — | $5M |
| 2024-Q1 | 12 | 4,342,972 | — | $11M |
| 2023-Q4 | 13 | 3,227,331 | — | $4M |
| 2023-Q3 | 15 | 3,278,548 | — | $4M |
| 2023-Q2 | 15 | 3,215,773 | — | $8M |
| 2023-Q1 | 15 | 2,396,538 | — | $10M |
| 2022-Q4 | 16 | 2,229,920 | — | $5M |
| 2022-Q3 | 18 | 2,172,626 | — | $12M |
