Latest Period
Q2 2026
Security Snapshot
Archimedes Tech SPAC Partners III Co. - Ordinary Shares, par value $0.0001 (ARCI) Institutional Ownership
CUSIP: G0453R105
13F Institutional Holders and Ownership History from Q1 2026 to Q2 2026
Institutions Reporting
52
Shares (Excl. Options)
20,236,815
Price
$10.01
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- Security type / class
- Equity / Ordinary Shares, par value $0.0001
- Symbol
- ARCI on Nasdaq
- All holders as of 30 Jun 2026
- Q2 2026
- Total 13F shares
- 20,236,815
- Total 13F value
- $202,644,072
- Portfolio coverage rank
- 0%
- Share change
- +4,178,910
- Value change
- +$41,953,542
- Number of holders
- 52
- Shares outstanding
- 35,294,118
- SEC-reported price per share
- $10.01
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
- ARCI - Archimedes Tech SPAC Partners III Co. - Ordinary Shares, par value $0.0001 is tracked under CUSIP G0453R105.
- 52 institutions reported positions in Q2 2026.
- 1 significant owner is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 40 to 52 between Q1 2026 and Q2 2026.
- SEC-reported value moved from $153,297,591 to $202,644,072.
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 52 institutions filings for Q2 2026.
Security key
G0453R105
Latest holder period
Q2 2026
13F holders
52
13D/G owners
1
CIK / CUSIP context first
Open Q2 2026 holders
ARCI full holder history
Archimedes Tech SPAC Partners III Co. SEC filings
Archimedes Tech SPAC Partners III Co. company facts
Archimedes Tech SPAC Partners III Co. insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP G0453R105:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
1
Security
ARCI
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| Adage Capital Management, L.P. | 5.1% | $17,730,000 | 1,800,000 | Adage Capital Management, L.P. | 31 Mar 2026 |
As of 30 Jun 2026, 52 institutional investors reported holding 20,236,815 shares of Archimedes Tech SPAC Partners III Co. - Ordinary Shares, par value $0.0001 (ARCI). This represents 57% of the company’s total 35,294,118 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
47%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 5.1% | 1,800,000 | 0% | 0.03% | $18,018,000 |
| Magnetar Financial LLC | 3.4% | 1,200,000 | 0% | 0.11% | $12,012,000 |
| Linden Advisors LP | 3.4% | 1,200,000 | 0% | 0.06% | $12,012,000 |
| Governors Lane LP | 3.2% | 1,146,610 | +15% | 1.1% | $11,477,566 |
| Alberta Investment Management Corp | 2.8% | 1,000,000 | 0.06% | $10,010,000 | |
| TENOR CAPITAL MANAGEMENT Co., L.P. | 2.8% | 1,000,000 | 0% | 0.14% | $10,010,000 |
| Verition Fund Management LLC | 2.3% | 815,355 | +8.7% | 0.06% | $8,161,704 |
| SONA ASSET MANAGEMENT (US) LLC | 2.3% | 800,000 | 0% | 0.3% | $8,008,000 |
| AQR Arbitrage LLC | 2.1% | 757,612 | 0.11% | $7,583,696 | |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 1.6% | 550,000 | 0% | 0.01% | $5,505,500 |
| Shaolin Capital Management LLC | 1.4% | 510,386 | -5.6% | 0.48% | $5,108,964 |
| Radcliffe Capital Management, L.P. | 1.4% | 504,673 | +22% | 0.38% | $5,051,777 |
| MOORE CAPITAL MANAGEMENT, LP | 1.4% | 500,000 | 0% | 0.11% | $5,005,000 |
| Polar Asset Management Partners Inc. | 1.4% | 500,000 | 0% | 0.09% | $5,005,000 |
| RIVERNORTH CAPITAL MANAGEMENT, LLC | 1.4% | 500,000 | 0.24% | $5,085,000 | |
| GLAZER CAPITAL, LLC | 1.4% | 496,809 | -1.5% | 0.12% | $4,973,000 |
| BNP PARIBAS FINANCIAL MARKETS | 1.4% | 492,372 | 0% | 0% | $4,928,644 |
| D. E. Shaw & Co., Inc. | 1.3% | 450,500 | +6% | 0% | $4,509,505 |
| Meteora Capital, LLC | 1.2% | 424,489 | -12% | 0.35% | $4,249,135 |
| Periscope Capital Inc. | 1.2% | 409,001 | 0% | 0.65% | $4,094,100 |
| COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS | 1.1% | 400,000 | 0.02% | $4,004,000 | |
| K2 PRINCIPAL FUND, L.P. | 0.87% | 308,333 | +2.9% | 0.37% | $3,086,413 |
| Hudson Bay Capital Management LP | 0.85% | 300,000 | 0% | 0.01% | $3,003,000 |
| MMCAP International Inc. SPC | 0.85% | 300,000 | 0.25% | $3,003,000 | |
| Schonfeld Strategic Advisors LLC | 0.84% | 297,404 | 0.02% | $2,977,014 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
2
Latest
Q2 2026
Rows shown
1-2 of 2