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Archimedes Tech SPAC Partners II Co.

ATIIW
Exchange
Nasdaq
Industry
Blank Checks
SEC CIK
0002028516

No open-market purchases or sales by Archimedes Tech SPAC Partners II Co. insiders were filed in the last 90 days; 33 institutions reported holding it in 13F filings for Q2 2026, worth $18.1M in total; no superinvestor holds it.

Other share classesATIIATIIU

13F holders, Q3 2025

Institutional positions in Archimedes Tech SPAC Partners II Co. as of Sep 30, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Institutional holders
35
0 vs. Q2 2025
Shares held
9.99M
+218.1K (+2.2%) vs. Q2 2025
Total value
$3.70M
+$518 (0.0%) vs. Q2 2025
New holders
5
4 more added
Sold out
5
8 more reduced

1 institution that held it in Q2 2025 haven't filed for Q3 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q2 2025: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting ATIIW on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holdersQ3 2025: 35 institutions
Q1 2021: 0 institutionsQ2 2021: 0 institutionsQ3 2021: 0 institutionsQ4 2021: 0 institutionsQ1 2022: 0 institutionsQ2 2022: 0 institutionsQ3 2022: 0 institutionsQ4 2022: 0 institutionsQ1 2023: 0 institutionsQ2 2023: 0 institutionsQ3 2023: 0 institutionsQ4 2023: 0 institutionsQ1 2024: 0 institutionsQ2 2024: 0 institutionsQ3 2024: 0 institutionsQ4 2024: 0 institutionsQ1 2025: 0 institutionsQ2 2025: 36 institutionsQ3 2025: 35 institutionsQ4 2025: 37 institutionsQ1 2026: 37 institutionsQ2 2026: 33 institutions
Value heldQ3 2025: $3.70M
Q1 2021: $0Q2 2021: $0Q3 2021: $0Q4 2021: $0Q1 2022: $0Q2 2022: $0Q3 2022: $0Q4 2022: $0Q1 2023: $0Q2 2023: $0Q3 2023: $0Q4 2023: $0Q1 2024: $0Q2 2024: $0Q3 2024: $0Q4 2024: $0Q1 2025: $0Q2 2025: $3.76MQ3 2025: $3.70MQ4 2025: $5.56MQ1 2026: $5.08MQ2 2026: $18.1M
Institutions holding ATIIW and their total value by quarter
QuarterHoldersValue
Q2 202633$18.1M
Q1 202637$5.08M
Q4 202537$5.56M
Q3 202535$3.70M
Q2 202536$3.76M
Q1 20250$0
Q4 20240$0
Q3 20240$0
Q2 20240$0
Q1 20240$0
Q4 20230$0
Q3 20230$0
Q2 20230$0
Q1 20230$0
Q4 20220$0
Q3 20220$0
Q2 20220$0
Q1 20220$0
Q4 20210$0
Q3 20210$0
Q2 20210$0
Q1 20210$0

Institutions, Q3 2025

Shares, value and share of portfolio for each institution holding Archimedes Tech SPAC Partners II Co.; share changes are against Q2 2025.

Institutions holding ATIIW in Q3 2025
InstitutionSharesValue% of portfolioChange in sharesAction
Harraden Circle Investments, LLC1,684,715$623.4K0.12%+644,715+62.0%Added
Tenor Capital Management Co., L.P.750,000$292.5K0.00%00.0%Unchanged
Magnetar Financial LLC650,000$240.5K0.00%00.0%Unchanged
Linden Advisors LP585,196$216.6K0.00%+85,197+17.0%Added
Shaolin Capital Management LLC550,000$214.5K0.01%−34,603−5.9%Reduced
CSS LLC532,646$207.7K0.01%00.0%Unchanged
CNH Partners LLC489,691$191.0K0.00%−161,927−24.8%Reduced
Healthcare of Ontario Pension Plan Trust Fund500,000$187.4K0.00%00.0%Unchanged
LMR Partners LLP425,000$165.8K0.00%00.0%Unchanged
Alberta Investment Management Corp375,000$146.3K0.00%00.0%Unchanged
Driehaus Capital Management LLC400,000$140.0K0.00%00.0%Unchanged
D. E. Shaw & Co., Inc.287,500$107.8K0.00%00.0%Unchanged
K2 Principal Fund, L.P.259,895$91.0K0.01%00.0%Unchanged
Moore Capital Management, LP225,000$87.8K0.00%00.0%Unchanged
Periscope Capital Inc.198,600$73.5K0.02%−25,000−11.2%Reduced
Governors Lane LP197,403$73.1K0.01%00.0%Unchanged
Westchester Capital Management, LLC199,999$70.0K0.00%00.0%Unchanged
Rivernorth Capital Management, LLC178,875$62.6K0.00%+178,875New
BNP Paribas Arbitrage, SA161,927$59.9K0.00%+161,927New
Clear Street Group Inc.130,840$51.0K0.00%+130,840New
Whitebox Advisors LLC125,000$48.8K0.00%00.0%Unchanged
Glazer Capital, LLC135,048$47.0K0.00%−114,890−46.0%Reduced
Picton Mahoney Asset Management125,000$47.0K0.00%00.0%Unchanged
Aristeia Capital LLC125,000$46.3K0.00%00.0%Unchanged
Parallax Volatility Advisers, L.P.123,890$45.8K0.00%+68,300+122.9%Added
Schonfeld Strategic Advisors LLC109,350$40.5K0.00%−25,650−19.0%Reduced
Verition Fund Management LLC104,800$39.3K0.00%+4,800+4.8%Added
MMCAP International Inc. SPC62,500$24.4K0.00%+62,500New
Gritstone Asset Management LLC49,540$19.3K0.02%−460−0.9%Reduced
Hudson Bay Capital Management LP39,994$15.6K0.00%00.0%Unchanged
Toronto Dominion Bank31,270$12.2K0.00%−100−0.3%Reduced
Readystate Asset Management LP25,000$9.37K0.00%+25,000New
Highbridge Capital Management LLC–$3.79K0.00%––
Wolverine Asset Management LLC3,521$1.37K0.00%−2,000−36.2%Reduced
Mint Tower Capital Management B.V.150,000––00.0%Unchanged
Sculptor Capital LP0$00.00%−595,760−100.0%Sold out
Centiva Capital, LP0$00.00%−75,000−100.0%Sold out
Mizuho Securities USA LLC0$00.00%−85,197−100.0%Sold out
Commonwealth of Pennsylvania Public School Empls Retrmt Sys0$00.00%−22,557−100.0%Sold out
UBS Group AG0$00.00%−874−100.0%Sold out
Clear Street LLC––––Not filed