% 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 ARMP 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 |
|---|---|---|---|---|---|---|---|
| Madison Asset Management, LLC | — | — | — | — | — | 2.1M | $22M |
| VANGUARD CAPITAL MANAGEMENT LLC | — | — | — | — | — | 366K | $4M |
| MILLENNIUM MANAGEMENT LLC | — | — | — | — | 26K | 258K | $3M |
| 683 Capital Management, LLC | — | — | — | — | 140K | 137K | $1M |
| GEODE CAPITAL MANAGEMENT, LLC | 107K | 106K | 105K | 105K | 110K | 115K | $1M |
| EDGEWOOD MANAGEMENT LLC | 100K | 100K | 100K | 100K | 100K | 100K | $1M |
| Dauntless Investment Group, LLC | — | — | — | — | 6K | 91K | $927,539 |
| SEI INVESTMENTS CO | — | — | — | — | — | 74K | $759,726 |
| VANGUARD FIDUCIARY TRUST CO | — | — | — | — | — | 68K | $694,927 |
| BlackRock, Inc. | 24K | 23K | 26K | 27K | 73K | 65K | $666,111 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | 50K | 28K | — | — | 24K | 65K | $663,132 |
| Informed Momentum Co LLC | — | — | — | — | — | 61K | $624,179 |
| GOLDMAN SACHS GROUP INC | — | — | — | — | 45K | 61K | $624,159 |
| STATE STREET CORP | 40K | 40K | 40K | 40K | 51K | 51K | $520,192 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 70K | 45K | 45K | 45K | 45K | 45K | $457,544 |
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 | |
|---|---|---|---|
| Madison Asset Management, LLC | +2,107,675 | — | OPEN |
| VANGUARD CAPITAL MANAGEMENT LLC | +366,028 | — | OPEN |
| MILLENNIUM MANAGEMENT LLC | +231,904 | — | ADD |
| Dauntless Investment Group, LLC | +84,449 | — | ADD |
| SEI INVESTMENTS CO | +74,192 | — | OPEN |
| Biggest sellers | Δ shares | Δ value | |
|---|---|---|---|
| VANGUARD GROUP INC | −357,649 | — | CLOSE |
| RENAISSANCE TECHNOLOGIES LLC | −30,000 | — | TRIM |
| OMERS ADMINISTRATION Corp | −28,125 | — | CLOSE |
| CITADEL ADVISORS LLC | −10,786 | — | CLOSE |
| BlackRock, Inc. | −7,714 | — | 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).
| Quarter | Holders | Shares held | % shares out | Value held |
|---|---|---|---|---|
| 2026-Q1 | 45 | 3,927,411 | — | $40M |
| 2025-Q4 | 36 | 1,247,603 | — | $8M |
| 2025-Q3 | 28 | 759,773 | — | $2M |
| 2025-Q2 | 29 | 735,244 | — | $1M |
| 2025-Q1 | 26 | 741,798 | — | $1M |
| 2024-Q4 | 24 | 1,390,254 | — | $3M |
| 2024-Q3 | 24 | 1,385,121 | — | $3M |
| 2024-Q2 | 23 | 1,404,525 | — | $4M |
| 2024-Q1 | 24 | 1,420,499 | — | $6M |
| 2023-Q4 | 25 | 1,288,987 | — | $4M |
| 2023-Q3 | 23 | 1,281,869 | — | $4M |
| 2023-Q2 | 22 | 1,185,533 | — | $1M |
| 2023-Q1 | 23 | 1,234,717 | — | $2M |
| 2022-Q4 | 26 | 1,303,460 | — | $2M |
| 2022-Q3 | 20 | 1,358,507 | — | $6M |
| 2022-Q2 | 19 | 1,349,947 | — | $5M |
| 2022-Q1 | 20 | 1,352,055 | — | $7M |
| 2021-Q4 | 17 | 1,334,337 | — | $7M |
| 2021-Q3 | 20 | 1,192,434 | — | $4M |
| 2021-Q2 | 21 | 1,157,116 | — | $5M |
| 2021-Q1 | 23 | 1,175,749 | — | $6M |
| 2020-Q4 | 19 | 871,498 | — | $3M |
| 2020-Q3 | 21 | 875,429 | — | $3M |
| 2020-Q2 | 21 | 858,774 | — | $3M |
| 2020-Q1 | 18 | 178,977 | — | $555,000 |
| 2019-Q4 | 16 | 163,857 | — | $532,000 |
| 2019-Q3 | 14 | 131,881 | — | $486,000 |
| 2019-Q2 | 12 | 118,380 | — | $475,000 |
| 2019-Q1 | 1 | 157,638 | — | $47,000 |
