Archimedes Tech SPAC Partners ATII Institutional Ownership

NASDAQ ATII

$10.67 +0.01 (+0.09%)

At close: Sep 18, 2026 · 4:00 PM EDT

Institutions by Trading Activity

51 Institutions

Increased 16 31.4%

Unchanged 12 23.5%

Reduced 23 45.1%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

59.50%

▼-23.61 pp QoQ

Shares Held by Institutions

17.61Mn

of 29.59Mn outstanding

▲+0.81% QoQ

Shares Outstanding

29.59Mn

11.98Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

▼-3 vs prior quarter

Net Shares Added (QoQ)

+140.71K

accumulated since last quarter

Value of Holdings

$187.87Mn

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

Quarter ending 30 Jun, 2026

Archimedes Tech SPAC Partners II Co. (NASDAQ:ATII) appears in 51 institutional 13F filings for the quarter ending June 2026.

These investors collectively held 59.5% of Archimedes Tech SPAC Partners's outstanding shares in June 2026, down from 83.1% in March 2026.
Their total shares held in ATII increased 0.81% quarter over quarter, and separately, investors owning Archimedes Tech SPAC Partners increased 24.39% from a year ago.
Of these 51 holders, 16 added to their stakes in Archimedes Tech SPAC Partners, 23 trimmed positions, and 12 made no changes.
In total, institutional investors held 17.61Mn shares in Archimedes Tech SPAC Partners as of June 2026, up by 140.71K shares quarter on quarter, and down 5.11Mn shares year over year.
As of June 30, 2026, the biggest holder of Archimedes Tech SPAC Partners is TENOR CAPITAL MANAGEMENT Co., L.P. at 1.37Mn shares, representing 4.62% of shares outstanding.
The biggest buyers of Archimedes Tech SPAC Partners for the quarter ending June 2026 included Fort Baker Capital Management LP (1.33Mn), Decagon Asset Management LLP (937.83K), Shay Capital LLC (623.69K), K2 PRINCIPAL FUND, L.P. (438.33K), FNY Investment Advisers, LLC (327.2K).
The largest sales of ATII for the quarter ending June 2026 came from GLAZER CAPITAL, LLC (699.9K), Toronto Dominion Bank (567.45K), LMR Partners LLP (371.02K), Alberta Investment Management Corp (350.0K), AQR Arbitrage LLC (330.41K).
Archimedes Tech SPAC Partners's 10 largest shareholders as of June 2026 include TENOR CAPITAL MANAGEMENT Co., L.P. (1.37Mn), Fort Baker Capital Management LP (1.33Mn), Magnetar Financial LLC (1.3Mn), D. E. Shaw & Co., Inc. (1.14Mn), Decagon Asset Management LLP (937.83K), LINDEN ADVISORS LP (848.27K), Ghisallo Capital Management LLC (800.0K), TWO SIGMA INVESTMENTS, LP (725.0K), Hudson Bay Capital Management LP (700.0K), Shay Capital LLC (623.69K) per Business Quant data.

Form 13F Holdings

50 Institutional Holders

Report period 30 Jun, 2026

Total shares held 17.61Mn

Of outstanding 59.50%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	TENOR CAPITAL MANAGEMENT Co., L.P.	0001346554	1,367,830	4.62%	▼132,170	-8.81%	$14.75Mn
2	Fort Baker Capital Management LP	0001688382	1,330,746	4.50%	▲1,330,746	0.00%	$14.35Mn
3	Magnetar Financial LLC	0001352851	1,297,302	4.38%	▼2,698	-0.21%	$13.98Mn
4	D. E. Shaw & Co., Inc.	0001009207	1,138,500	3.85%	0	0.00%	$12.27Mn
5	Decagon Asset Management LLP	0001950677	937,829	3.17%	▲937,829	0.00%	$10.11Mn
6	LINDEN ADVISORS LP	0001279396	848,273	2.87%	▼151,727	-15.17%	$9.14Mn
7	Ghisallo Capital Management LLC	0001825214	800,000	2.70%	0	0.00%	$8.62Mn
8	TWO SIGMA INVESTMENTS, LP	0001179392	725,000	2.45%	0	0.00%	$7.82Mn
9	Hudson Bay Capital Management LP	0001393825	700,000	2.37%	0	0.00%	$7.55Mn
10	Shay Capital LLC	0001723643	623,687	2.11%	▲623,687	0.00%	$6.72Mn
11	Governors Lane LP	0001644187	604,857	2.04%	▼154,699	-20.37%	$6.52Mn
12	AQR Arbitrage LLC	0001167456	590,262	1.99%	▼330,410	-35.89%	$6.36Mn
13	Sculptor Capital LP	0001054587	552,619	1.87%	▼48,027	-8.00%	$5.96Mn
14	K2 PRINCIPAL FUND, L.P.	0001461790	526,227	1.78%	▲438,327	+498.67%	$5.67Mn
15	LMR Partners LLP	0001578621	478,978	1.62%	▼371,022	-43.65%	$5.16Mn
16	Radcliffe Capital Management, L.P.	0001218275	478,061	1.62%	▼183,276	-27.71%	$5.15Mn
17	MOORE CAPITAL MANAGEMENT, LP	0001448574	450,000	1.52%	0	0.00%	$4.85Mn
18	Alberta Investment Management Corp	0001463559	400,000	1.35%	▼350,000	-46.67%	$4.31Mn
19	FNY Investment Advisers, LLC	0001742998	327,200	1.11%	▲327,200	0.00%	$3.53K
20	Mint Tower Capital Management B.V.	0001666606	300,000	1.01%	0	0.00%	$3.23K

Showing 1 to 20 of 50 holders