ARCI · Archimedes Tech SPAC Partners III Co. · Shareholders & Ownership
Market Cap
$354.03M
Shares
35.26M
Volume · Oct 22
69.8K
Avg daily vol (3M)
73.45K
Every disclosed holder of ARCI in one list: 13F institutions, Schedule 13D and 13G filers, insiders (Forms 3, 4 and 5) and registered funds, each from its own latest filing. Holders nest by CIK and SEC reporting links, never by name, and each is summed once.
Who Owns ARCI
13F quarter Sep 30, 2026, combined view: filers that have not filed yet carry their Jun 30, 2026 positions| Holder group | Shares | % Out |
|---|---|---|
| Institutional (13F) | 29,666,023 | 84.13% |
| Insiders (Forms 3, 4, 5) | 780,000 | 2.21% |
| 13D/G-only blocks | 0 | 0.00% |
| Remaining | 4,815,977 | 13.66% |
| Registered funds (N-PORT, not summed) | 438,952 | 1.24% |
Shares outstanding: 35,262,000, the issuer's latest cover-page count restated onto today's split basis.
13D/G-only counts each filer's latest 13D or 13G that no 13F report of the listing contains, that names no 13F filer and that no counted insider files. Funds are never summed: their shares sit inside their advisers' 13F reports.
Holders of ARCI
| # | Holder | Shares | As of | Notes |
|---|---|---|---|---|
| 1 |
ADAGE CAPITAL PARTNERS GP, L.L.C.
13F
CIK 1165408 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
2,000,000 | ||
| 2 |
Magnetar Financial LLC
13F
CIK 1352851 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
1,500,000 | ||
| 3 |
Linden Advisors LP
13F
CIK 1279396 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
1,499,999 | ||
| 4 |
Governors Lane LP
13F
CIK 1644187 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
1,396,610 | ||
| 5 |
Alberta Investment Management Corp
13F
CIK 1463559 · Non-US institution · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
1,250,000 | ||
| 6 |
LMR Partners LLP
13F
CIK 1578621 · Exempt reporting adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,250,000 | ||
| 7 |
TENOR CAPITAL MANAGEMENT Co., L.P.
13F
CIK 1346554 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
1,250,000 | ||
| 8 |
Verition Fund Management LLC
13F
CIK 1454027 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
1,002,555 | ||
| 9 |
SONA ASSET MANAGEMENT (US) LLC
13F
CIK 1856405 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
1,000,000 | ||
| 10 |
AQR Arbitrage LLC
13F
CIK 1167456 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
947,015 | ||
| 11 |
TORONTO DOMINION BANK
13F
CIK 947263 · Bank · Jun 30, 2026
Classes ARCI, ARCIU, carried, not yet filed for the newest quarter
|
822,133 | ||
| 12 |
HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND
13F
CIK 1535845 · Non-US institution · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
687,500 | ||
| 13 |
TUDOR INVESTMENT CORP ET AL
13F
CIK 923093 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
650,000 | ||
| 14 |
Polar Asset Management Partners Inc.
13F
CIK 1326389 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
629,300 | ||
| 15 |
Shaolin Capital Management LLC
13F
CIK 1766806 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
625,106 | ||
| 16 |
MOORE CAPITAL MANAGEMENT, LP
13F
CIK 1448574 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
625,000 | ||
| 17 |
RIVERNORTH CAPITAL MANAGEMENT, LLC
13F
CIK 1447578 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
625,000 | ||
| 18 |
K2 PRINCIPAL FUND, L.P.
13F
CIK 1461790 · Unknown · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
617,170 | ||
| 19 |
BNP PARIBAS ARBITRAGE, SA
13F
CIK 1166588 · Unknown · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
615,465 | ||
| 20 |
Radcliffe Capital Management, L.P.
13F
CIK 1218275 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
586,058 | ||
| 21 |
GLAZER CAPITAL, LLC
13F
CIK 1076809 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIU, ARCIW, carried, not yet filed for the newest quarter
|
557,332 | ||
| 22 |
D. E. Shaw & Co., Inc.
13F
CIK 1009207 · Unknown · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
556,750 | ||
| 23 |
Periscope Capital Inc.
13F
CIK 1695320 · Exempt reporting adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
510,101 | ||
| 24 |
METEORA CAPITAL, LLC
13F
CIK 1905106 · Investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
508,474 | ||
| 25 |
COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS
13F
CIK 1083190 · Unknown · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
500,000 | ||
| 26 |
OMERS ADMINISTRATION Corp
13F
CIK 1053321 · Pension or benefit plan · Jun 30, 2026
carried, not yet filed for the newest quarter
|
480,000 | ||
| 27 |
ARISTEIA CAPITAL, L.L.C.
13F
CIK 1080171 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
400,779 | ||
| 28 |
Centiva Capital, LP
13F
CIK 1692507 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
394,489 | ||
| 29 |
|
390,000 | ||
| 30 |
|
390,000 | ||
| 31 |
MMCAP International Inc. SPC
13F
CIK 1304857 · Unknown · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
375,000 | ||
| 32 |
Schonfeld Strategic Advisors LLC
13F
CIK 1665241 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
337,404 | ||
| 33 |
MILLENNIUM MANAGEMENT LLC
13F
CIK 1273087 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIU, carried, not yet filed for the newest quarter
|
329,743 | ||
| 34 |
HBK INVESTMENTS L P
13F
CIK 1011443 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
312,505 | ||
| 35 |
Hudson Bay Capital Management LP
13F
CIK 1393825 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
300,000 | ||
| 36 |
Lineage Point Capital LP
13F
CIK 2093311 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
288,776 | ||
| 37 |
BlueCrest Capital Management Ltd
13F
CIK 1610880 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
275,000 | ||
| 38 |
TWO SIGMA INVESTMENTS, LP
13F
CIK 1179392 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
273,791 | ||
| 39 |
683 Capital Management, LLC
13F
CIK 1404574 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
250,000 | ||
| 40 |
Ghisallo Capital Management LLC
13F
CIK 1825214 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
250,000 | ||
| 41 |
BERKLEY W R CORP
13F
CIK 11544 · Insurance company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
248,000 | ||
| 42 |
Clear Street Group Inc.
13F
CIK 1881567 · Unknown · Jun 30, 2026
Classes ARCI, ARCIU, ARCIW, carried, not yet filed for the newest quarter
|
237,072 | ||
| 43 |
DLD Asset Management, LP
13F
CIK 1578299 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
212,499 | ||
| 44 |
Wealthspring Capital LLC
13F
CIK 1844495 · Registered investment adviser · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
201,830 | ||
| 45 |
First Trust Capital Management L.P.
13F
CIK 1604488 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
200,000 | ||
| 46 |
MANGROVE PARTNERS IM, LLC
13F
CIK 1535392 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
200,000 | ||
| 47 |
Mint Tower Capital Management B.V.
13F
CIK 1666606 · Unknown · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
187,500 | ||
| 48 |
PICTON MAHONEY ASSET MANAGEMENT
13F
CIK 1539041 · Non-US institution · Jun 30, 2026
Classes ARCI, ARCIW, carried, not yet filed for the newest quarter
|
187,495 | ||
| 49 |
First Trust Merger Arbitrage Fund
Fund
S000048195 · Registered fund · Jun 30, 2026
INVESTMENT MANAGERS SERIES TRUST II, not summed
|
171,728 | ||
| 50 |
StoneX Group Inc.
13F
CIK 913760 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
150,309 |
Shares are restated onto today's split basis. Change compares each row with the same holder's previous filing in the same source; a dash means there is none to compare. Nested 13D/G, insider and fund rows are not summed, since a 13F report already holds them.
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