Latest Period
Q1 2026
Security Snapshot
Archimedes Tech SPAC Partners II Co. - COMMON-STOCK (ATII) Institutional Ownership
CUSIP: G04537109
13F Institutional Holders and Ownership History from Q2 2025 to Q2 2026
Institutions Reporting
54
Shares (Excl. Options)
22,185,740
Price
$10.41
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- Security type / class
- Equity / COMMON-STOCK
- Symbol
- ATII on Nasdaq
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 22,185,740
- Total 13F value
- $231,266,965
- Portfolio coverage rank
- 0%
- Share change
- -497,798
- Value change
- -$5,138,304
- Number of holders
- 54
- Shares outstanding
- 29,602,835
- SEC-reported price per share
- $10.78
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
2 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- ATII - Archimedes Tech SPAC Partners II Co. - COMMON-STOCK is tracked under CUSIP G04537109.
- 54 institutions reported positions in Q1 2026.
- 1 significant owner is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 54 to 6 between Q1 2026 and Q2 2026.
- SEC-reported value moved from $231,266,965 to $13,805,878.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 54 institutions filings for Q1 2026.
Security key
G04537109
Latest holder period
Q1 2026
13F holders
54
13D/G owners
1
CIK / CUSIP context first
Open Q1 2026 holders
ATII full holder history
Archimedes Tech SPAC Partners II Co. SEC filings
Archimedes Tech SPAC Partners II Co. company facts
Archimedes Tech SPAC Partners II Co. insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP G04537109:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
1
Security
ATII
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| BARCLAYS PLC | 3.9% | -40% | $11,899,392 | -$7,415,843 | 1,148,590 | -38% | Barclays PLC | 31 Dec 2025 |
As of 31 Mar 2026, 54 institutional investors reported holding 22,185,740 shares of Archimedes Tech SPAC Partners II Co. - COMMON-STOCK (ATII). This represents 75% of the company’s total 29,602,835 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
60%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| TENOR CAPITAL MANAGEMENT Co., L.P. | 5.1% | 1,500,000 | 0% | 0.25% | $15,615,000 |
| Magnetar Financial LLC | 4.4% | 1,300,000 | 0% | 0.14% | $13,565,500 |
| D. E. Shaw & Co., Inc. | 3.8% | 1,138,500 | 0% | 0.01% | $11,897,325 |
| Linden Advisors LP | 3.4% | 1,000,000 | 0% | 0.06% | $10,435,000 |
| AQR Arbitrage LLC | 3.1% | 920,672 | -4.5% | 0.16% | $9,584,196 |
| Westchester Capital Management, LLC | 3.1% | 907,144 | 0% | 0.46% | $9,443,369 |
| LMR Partners LLP | 2.9% | 850,000 | 0% | 0.08% | $8,848,500 |
| Ghisallo Capital Management LLC | 2.7% | 800,000 | 0% | 0.23% | $8,348,000 |
| Governors Lane LP | 2.6% | 759,556 | +0.12% | 0.99% | $7,925,967 |
| Alberta Investment Management Corp | 2.5% | 750,000 | 0% | 0.05% | $7,837,500 |
| GLAZER CAPITAL, LLC | 2.5% | 750,000 | -13% | 0.17% | $7,808,000 |
| TWO SIGMA INVESTMENTS, LP | 2.4% | 725,000 | 0% | 0.01% | $7,547,250 |
| Hudson Bay Capital Management LP | 2.4% | 700,000 | 0% | 0.04% | $7,315,000 |
| Radcliffe Capital Management, L.P. | 2.2% | 661,337 | +0.46% | 0.52% | $6,901,052 |
| TORONTO DOMINION BANK | 2.2% | 650,000 | +333% | 0.01% | $6,766,500 |
| Sculptor Capital LP | 2% | 600,646 | 0% | 0.07% | $6,252,725 |
| PICTON MAHONEY ASSET MANAGEMENT | 1.7% | 500,000 | 0% | 0.05% | $5,205,000 |
| Jain Global LLC | 1.7% | 500,000 | 0% | 0.07% | $5,217,500 |
| MOORE CAPITAL MANAGEMENT, LP | 1.5% | 450,000 | 0% | 0.17% | $4,684,500 |
| RIVERNORTH CAPITAL MANAGEMENT, LLC | 1.4% | 427,500 | -4.5% | 0.22% | $4,450,275 |
| RLH Capital LLC | 1.4% | 400,907 | 0% | 2.1% | $4,183,465 |
| COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS | 1.4% | 400,000 | 0% | 0.02% | $4,174,000 |
| J. Goldman & Co LP | 1.2% | 369,778 | 0.18% | $3,849,389 | |
| Periscope Capital Inc. | 1.2% | 352,880 | -21% | 0.64% | $3,682,303 |
| GOLDMAN SACHS GROUP INC | 1.1% | 327,450 | +1.1% | 0% | $3,408,755 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
5
Latest
Q1 2026
Rows shown
1-5 of 5
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q2 | 1,281,400 | $13,805,878 | -$634,595 | $10.78 | 6 |
| 2026 Q1 | 22,185,740 | $231,266,965 | -$5,138,304 | $10.41 | 54 |
| 2025 Q4 | 22,244,887 | $230,423,429 | +$304,225 | $10.36 | 49 |
| 2025 Q3 | 22,015,854 | $224,953,929 | +$9,215,998 | $10.21 | 46 |
| 2025 Q2 | 21,123,433 | $215,981,429 | +$211,385,929 | $10.23 | 42 |