% 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 IMSRW 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 | LMR Partners LLP | 3,347,5103.3M | $9M | — | ADD 17% |
| 2 | Hudson Bay Capital Management LP | 1,303,0501.3M | $3M | — | ADD 427% |
| 3 | PEAK6 LLC | 1,186,1461.2M | $3M | — | TRIM -50% |
| 4 | CANTOR FITZGERALD, L. P. | 1,083,0511.1M | $3M | — | TRIM -58% |
| 5 | BOOTHBAY FUND MANAGEMENT, LLC | 390,000390,000 | $2M | — | NEW |
| 6 | Caption Management, LLC | 865,372865,372 | $2M | — | ADD 7% |
| 7 | Magnetar Financial LLC | 780,000780,000 | $2M | — | TRIM -14% |
| 8 | ARISTEIA CAPITAL, L.L.C. | 735,393735,393 | $2M | — | ADD 263% |
| 9 | MORGAN STANLEY | 280,768280,768 | $727,189 | — | TRIM -18% |
| 10 | Linden Advisors LP | 194,560194,560 | $500,019 | — | — |
| 11 | Arosa Capital Management LP | 175,000175,000 | $453,250 | — | TRIM -36% |
| 12 | Walleye Capital LLC | 139,986139,986 | $362,564 | — | TRIM -9% |
| 13 | Periscope Capital Inc. | 152,500152,500 | $292,800 | — | — |
| 14 | CastleKnight Management LP | 73,20073,200 | $189,588 | — | — |
| 15 | Saba Capital Management, L.P. | 65,68165,681 | $170,114 | — | TRIM -13% |
| 16 | Alberta Investment Management Corp | 50,00050,000 | $129,500 | — | — |
| 17 | WOLVERINE ASSET MANAGEMENT LLC | 48,72248,722 | $126,190 | — | TRIM -32% |
| 18 | Balyasny Asset Management L.P. | 40,74340,743 | $104,913 | — | TRIM -81% |
| 19 | Virtu Financial LLC | 28,42128,421 | $74,000 | — | NEW |
| 20 | Stoic Point Capital Management LLC | 13,40213,402 | $34,711 | — | — |
| 21 | Clear Street Group Inc. | 10,00010,000 | $25,900 | — | — |
| 22 | Advisory Services Network, LLC | 6,0506,050 | $15,670 | — | NEW |
| 23 | Rockefeller Capital Management L.P. | 6,0006,000 | $15,540 | — | NEW |
| 24 | Federation des caisses Desjardins du Quebec | 2,0002,000 | $5,180 | — | NEW |
| 25 | OSAIC HOLDINGS, INC. | 600600 | $1,554 | — | — |
| 26 | SUMMIT SECURITIES GROUP LLC | 11 | $3 | — | — |
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 |
|---|---|---|---|---|---|---|---|
| LMR Partners LLP | 750K | 1.1M | 1.6M | 1.6M | 2.9M | 3.3M | $9M |
| Hudson Bay Capital Management LP | — | — | — | — | 247K | 1.3M | $3M |
| PEAK6 LLC | — | — | 1.2M | 2.3M | 2.4M | 1.2M | $3M |
| CANTOR FITZGERALD, L. P. | 2.8M | 2.9M | 2.8M | 2.7M | 2.6M | 1.1M | $3M |
| BOOTHBAY FUND MANAGEMENT, LLC | — | — | — | 11K | — | 390K | $2M |
| Caption Management, LLC | — | — | — | — | 807K | 865K | $2M |
| Magnetar Financial LLC | — | 980K | 980K | 675K | 905K | 780K | $2M |
| ARISTEIA CAPITAL, L.L.C. | — | — | — | 229K | 202K | 735K | $2M |
| MORGAN STANLEY | — | — | 283K | 283K | 342K | 281K | $727,189 |
| Linden Advisors LP | — | 500K | 500K | 450K | 195K | 195K | $500,019 |
| Arosa Capital Management LP | — | — | 450K | 450K | 275K | 175K | $453,250 |
| Walleye Capital LLC | — | — | — | — | 155K | 140K | $362,564 |
| Periscope Capital Inc. | 298K | 179K | 33K | — | 153K | 153K | $292,800 |
| CastleKnight Management LP | — | — | — | 153K | 73K | 73K | $189,588 |
| Saba Capital Management, L.P. | — | 11K | 49K | 49K | 76K | 66K | $170,114 |
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 | 26 | 10,978,156 | — | $30M |
| 2025-Q4 | 27 | 11,826,625 | — | $25M |
| 2025-Q3 | 24 | 10,710,036 | — | $64M |
| 2025-Q2 | 31 | 12,377,209 | — | $29M |
| 2025-Q1 | 29 | 11,477,742 | — | $32M |
| 2024-Q4 | 22 | 8,821,270 | — | $728,870 |
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 | |
|---|---|---|---|
| Hudson Bay Capital Management LP | +1,055,650 | — | ADD |
| ARISTEIA CAPITAL, L.L.C. | +532,912 | — | ADD |
| LMR Partners LLP | +496,900 | — | ADD |
| BOOTHBAY FUND MANAGEMENT, LLC | +390,000 | — | OPEN |
| Caption Management, LLC | +58,829 | — | ADD |
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| CANTOR FITZGERALD, L. P. | −1,491,949 | — | TRIM |
| PEAK6 LLC | −1,186,146 | — | TRIM |
| Balyasny Asset Management L.P. | −173,170 | — | TRIM |
| Magnetar Financial LLC | −124,994 | — | TRIM |
| Arosa Capital Management LP | −100,000 | — | 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 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).
