Institutional HoldersBeta

Who holds a company, from every 13F filed for the quarter, one row per filer exactly as filed, against the latest share count the company reported.

Archimedes Tech SPAC Partners II Co.

CIK 0002028516ATIIATIIUATIIW· quarter ending 2026-06-30

Shares outstanding

29,590,000

as of 2026-08-13 · 10-Q cover page, filed 2026-08-13

Held by 13F filers

8,367,108

selection includes debt or preferreds — no % of shares outstanding

Holders

-4 vs 2026-03-31 · 7 new, 11 exited

Value

$18.1M

shares -18.4% vs prior quarter

Share classes (cover page of the 10-Q filed 2026-08-13, as of 2026-08-13)

Class	Listed	Shares outstanding	Held by 13F filers	% of class	Holders	CUSIP
Common stock	ATII · NASDAQ	29,590,000	17,695,127	59.8%	51	G04537109

Each class is compared with its own share count; classes are not added together. A class that is not exchange-listed cannot be held by 13F filers.

Securities (CUSIPs held in 13F this quarter)

tick to combine

CUSIP	Class (as filers write it)	Holders	Shares held	Class shares	% of class	Value	Options	Mapped via
G04537109	COM	51	17,695,127	29,590,000	59.8%	$190.7M	—	13DG	holders →
G04537125	*W EXP 10/15/202not common	33	8,366,999 $109 principal	—	—	$18.1M	1 call / 0 put	NPORT	holders →
G04537117	UNIT 10/15/2029not common	4	110,365	—	—	$1.3M	—	13DG	holders →

Totals combine the ticked CUSIPs and update as you tick: common-stock classes by default; preferreds, notes, warrants and depositary shares are listed but not counted. "holders →" shows a single CUSIP on its own. Bonds are held as a principal amount, not shares. Options positions are never counted as holdings.

Top holders (33 of 33 · G04537125)

change vs 2026-03-31

#	Filer	Shares / principal	% of class	Value	Change
1	Harraden Circle Investments, LLC	1,131,600	—	$2.5M	-478,115 (-29.7%)
2	ARISTEIA CAPITAL, L.L.C.	788,491	—	$1.7M	+663,491 (+530.8%)
3	TENOR CAPITAL MANAGEMENT Co., L.P.	750,000	—	$1.6M	—
4	LMR Partners LLP	613,701	—	$1.3M	+188,701 (+44.4%)
5	Linden Advisors LP	504,138	—	$1.1M	-356,824 (-41.4%)
6	HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND	500,000	—	$1.1M	—
7	AQR Arbitrage LLC	481,366	—	$1.0M	+2,158 (+0.5%)
8	Magnetar Financial LLC	437,600	—	$954K	-212,400 (-32.7%)
9	Alberta Investment Management Corp	375,000	—	$821K	—
10	Decagon Asset Management LLP	331,302	—	$726K	NEW
11	D. E. Shaw & Co., Inc.	287,500	—	$627K	—
12	K2 PRINCIPAL FUND, L.P.	280,718	—	$615K	+40,823 (+17.0%)
13	MOORE CAPITAL MANAGEMENT, LP	225,000	—	$493K	—
14	RIVERNORTH CAPITAL MANAGEMENT, LLC	224,942	—	$324K	—
15	Shaolin Capital Management LLC	181,640	—	$398K	-318,360 (-63.7%)
16	BNP PARIBAS FINANCIAL MARKETS	161,927	—	$355K	—
17	CSS LLC/IL	151,718	—	$332K	-335,901 (-68.9%)
18	Sculptor Capital LP	150,200	—	$329K	NEW
19	Mint Tower Capital Management B.V.	130,000	—	$285K	-20,000 (-13.3%)
20	WHITEBOX ADVISORS LLC	125,000	—	$274K	—
21	Alpine Global Management, LLC	71,039	—	$156K	NEW
22	DLD Asset Management, LP	69,400	—	$152K	-30,600 (-30.6%)
23	MMCAP International Inc. SPC	62,500	—	$137K	—
24	Clear Street Group Inc.	60,000	—	$131K	-93,619 (-60.9%)
25	SUSQUEHANNA INTERNATIONAL GROUP, LLP	48,825	—	$106K	NEW
26	Fort Baker Capital Management LP	41,177	—	$90K	NEW
27	Periscope Capital Inc.	40,000	—	$88K	-158,600 (-79.9%)
28	Hudson Bay Capital Management LP	39,994	—	$87K	—
29	Lineage Point Capital LP	35,771	—	$78K	-51,916 (-59.2%)
30	Centiva Capital, LP	31,450	—	$69K	NEW
31	Schonfeld Strategic Advisors LLC	30,000	—	$66K	-52,192 (-63.5%)
32	Thomas J. Herzfeld Advisors, Inc.	5,000	—	$11K	NEW
33	HIGHBRIDGE CAPITAL MANAGEMENT LLC	109	—	$219	-10,000 (-98.9%)

Exited since 2026-03-31 (11 filers; largest 11 shown)

TORONTO DOMINION BANK	−554,674
Westchester Capital Management, LLC	−199,999
Governors Lane LP	−197,403
PICTON MAHONEY ASSET MANAGEMENT	−125,000
Verition Fund Management LLC	−87,000
GRITSTONE ASSET MANAGEMENT LLC	−49,540
RLH Capital LLC	−47,382
READYSTATE ASSET MANAGEMENT LP	−25,000
GLAZER CAPITAL, LLC	−24,850
Quarry LP	−23,691
UBS Group AG	−2,963

Large holders from 13D/13G (latest per reporting person, last 2 years)

Filed when a holder crosses 5% or changes materially, so often more current than the quarter-end 13F. Percentages are the filer's own, against the share count they used.

Reporting person	Form	Filed	Event	Shares	% of class
Robin Shah	SCHEDULE 13G/A	2026-08-14	2026-06-30	1,367,830	4.6%
Tenor Capital Management Company, L.P.	SCHEDULE 13G/A	2026-08-14	2026-06-30	1,367,830	4.6%
Tenor Opportunity Master Fund, Ltd.	SCHEDULE 13G/A	2026-08-14	2026-06-30	1,367,830	4.6%
Barclays PLC	SCHEDULE 13G/A	2026-02-11	2025-12-31	1,148,590	3.88%
Sculptor Capital Holding Corp	SCHEDULE 13G/A	2025-08-14	2025-06-30	1,300,000	4.39%
Sculptor Capital Holding II LLC	SCHEDULE 13G/A	2025-08-14	2025-06-30	1,300,000	4.39%
Sculptor Capital II LP	SCHEDULE 13G/A	2025-08-14	2025-06-30	1,300,000	4.39%
Sculptor Capital LP	SCHEDULE 13G/A	2025-08-14	2025-06-30	1,300,000	4.39%
Sculptor Capital Management, Inc.	SCHEDULE 13G/A	2025-08-14	2025-06-30	1,300,000	4.39%
Sculptor Master Fund, Ltd.	SCHEDULE 13G/A	2025-08-14	2025-06-30	1,300,000	4.39%
Sculptor Special Funding, LP	SCHEDULE 13G/A	2025-08-14	2025-06-30	1,300,000	4.39%
TENOR CAPITAL MANAGEMENT COMPANY, LP	SCHEDULE 13G	2025-02-19	2025-02-11	1,500,000	5.8%

Source: SEC Form 13F-HR information tables for the quarter ending 2026-06-30 (filed within 45 days of quarter end; amendments applied; values normalised to dollars), the share count from the company's latest 10-K/10-Q XBRL cover page, and Schedule 13D/13G filings. Each row is a legal 13F filer as filed — related entities (e.g. Vanguard's advisers) are not merged. Retail brokerage accounts are not reported on 13F, so the remainder is mostly retail and insiders.