Archimedes Tech SPAC Partners III ARCI Institutional Ownership

NASDAQ ARCI

$10.04 -0.01 (-0.10%)

At close: Oct 29, 2026 · 4:00 PM EDT

Institutions by Trading Activity

51 Institutions

Increased 25 49.0%

Unchanged 22 43.1%

Reduced 4 7.8%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

57.29%

Shares Held by Institutions

20.20Mn

of 35.26Mn outstanding

■0.00% QoQ

Shares Outstanding

35.26Mn

15.06Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

Net Shares Added (QoQ)

+4.96Mn

accumulated since last quarter

Value of Holdings

$202.83Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 10, 2026

Archimedes Tech SPAC Partners III Co. (NASDAQ:ARCI) was held by 51 institutional investors that filed 13F reports for the quarter ended June 30, 2026.

These investors held 57.29% of Archimedes Tech SPAC Partners III's outstanding shares at the end of Q2 2026.
Combined, institutional investors held 20.2Mn shares of ARCI as of Q2 2026.
Adage Capital Partners GP, L.L.C. led 13F holders of ARCI with 1.8Mn shares as of June 30, 2026, or 5.10% of shares outstanding.
Holders that added the most shares of Archimedes Tech SPAC Partners III in Q2 2026 were Governors Lane LP (+146.61K shares), Radcliffe Capital Management, L.P. (+90.38K shares), Toronto Dominion Bank (+80.52K shares), Verition Fund Management LLC (+65.36K shares) and StoneX Group Inc. (+40.56K shares).
Among holders that kept a stake in Archimedes Tech SPAC Partners III, the biggest sellers in Q2 2026 were Clear Street Group Inc. (-93.15K shares), Meteora Capital, LLC (-59.25K shares), Shaolin Capital Management LLC (-30.07K shares) and Glazer Capital, LLC (-7.79K shares).
Business Quant data shows the 10 biggest positions in Archimedes Tech SPAC Partners III as of Q2 2026 were held by Adage Capital Partners GP, L.L.C. (1.8Mn shares), Linden Advisors LP (1.2Mn shares), Magnetar Financial LLC (1.2Mn shares), Governors Lane LP (1.15Mn shares), Tenor Capital Management Co., L.P. (1Mn shares), Alberta Investment Management Corp (1Mn shares), Verition Fund Management LLC (815.36K shares), Sona Asset Management (US) LLC (800K shares), AQR Arbitrage LLC (757.61K shares) and Healthcare of Ontario Pension Plan Trust Fund (550K shares).

Form 13F Holdings

51 Institutional Holders

Report period 30 Jun, 2026

Total shares held 20.20Mn

Of outstanding 57.29%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	ADAGE CAPITAL PARTNERS GP, L.L.C.	0001165408	1,800,000	5.10%	0	0.00%	$18.02Mn
2	Magnetar Financial LLC	0001352851	1,200,000	3.40%	0	0.00%	$12.01Mn
2	LINDEN ADVISORS LP	0001279396	1,200,000	3.40%	0	0.00%	$12.01Mn
3	Governors Lane LP	0001644187	1,146,610	3.25%	▲146,610	+14.66%	$11.48Mn
4	TENOR CAPITAL MANAGEMENT Co., L.P.	0001346554	1,000,000	2.84%	0	0.00%	$10.01Mn
4	Alberta Investment Management Corp	0001463559	1,000,000	2.84%	▲1,000,000	0.00%	$10.01Mn
5	Verition Fund Management LLC	0001454027	815,355	2.31%	▲65,355	+8.71%	$8.16Mn
6	SONA ASSET MANAGEMENT (US) LLC	0001856405	800,000	2.27%	0	0.00%	$8.01Mn
7	AQR Arbitrage LLC	0001167456	757,612	2.15%	▲757,612	0.00%	$7.58Mn
8	HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND	0001535845	550,000	1.56%	0	0.00%	$5.51Mn
9	Shaolin Capital Management LLC	0001766806	510,386	1.45%	▼30,068	-5.56%	$5.11Mn
10	Radcliffe Capital Management, L.P.	0001218275	504,673	1.43%	▲90,376	+21.81%	$5.05Mn
11	MOORE CAPITAL MANAGEMENT, LP	0001448574	500,000	1.42%	0	0.00%	$5.01Mn
11	RIVERNORTH CAPITAL MANAGEMENT, LLC	0001447578	500,000	1.42%	▲500,000	0.00%	$5.09Mn
11	Polar Asset Management Partners Inc.	0001326389	500,000	1.42%	0	0.00%	$5.01Mn
12	GLAZER CAPITAL, LLC	0001076809	496,809	1.41%	▼7,793	-1.54%	$4.97K
13	BNP PARIBAS FINANCIAL MARKETS	0001166588	492,372	1.40%	▲492,372	0.00%	$4.93Mn
14	D. E. Shaw & Co., Inc.	0001009207	450,500	1.28%	▲25,500	+6.00%	$4.51Mn
15	METEORA CAPITAL, LLC	0001905106	424,489	1.20%	▼59,251	-12.25%	$4.25Mn
16	PERISCOPE CAPITAL INC.	0001695320	409,001	1.16%	0	0.00%	$4.09Mn

Showing 1 to 20 of 51 holders