Archimedes Tech SPAC Partners II Co. (ATII) — Institutional Holders, Q2 2026
61 institutional investment managers reported a ATII position on SEC Form 13F-HR for the quarter ended June 30, 2026, with a combined reported value of $209.2M. Every filer is listed below, ranked by position value. Put and call option positions are excluded, and a firm filing several lots or share classes is shown once with its total.
ATII in Q2 2026: what funds did
Funds that filed a 13F for both Q1 2026 and Q2 2026, by what they did with the common stock. Share counts are adjusted for any split between the two quarters; dollar figures are the change in shares at this quarter’s price.
Biggest buyers
- Fort Baker Capital ManagementNew · +1,371,923 sh+$12.6M
- Decagon Asset Management LLPNew · +1,269,131 sh+$11.7M
- Shay CapitalNew · +623,687 sh+$5.7M
- ARISTEIA CAPITAL, L.L.C.Added · +613,491 sh+$5.6M
- K2 PRINCIPAL FUND, L.P.Added · +479,150 sh+$4.4M
Biggest sellers
- TORONTO DOMINION BANKTrimmed · -1,122,124 sh-$10.3M
- Westchester Capital ManagementSold out · -1,107,143 sh-$10.2M
- GLAZER CAPITALTrimmed · -724,750 sh-$6.7M
- PICTON MAHONEY ASSET MANAGEMENTSold out · -625,000 sh-$5.7M
- Shaolin Capital ManagementTrimmed · -512,972 sh-$4.7M
ATII 13F holders ranked 1–61 of 61
| # | Institution | Shares | Value | % of portfolio | QoQShares vs Q1 2026 |
|---|---|---|---|---|---|
| 1 | TENOR CAPITAL MANAGEMENT , L.P.#1 · 2,117,830 sh | 2,117,830 | $16.4M | 0.23% | -5.9% |
| 2 | Magnetar Financial#2 · 1,734,902 sh | 1,734,902 | $14.9M | 0.14% | -11.0% |
| 3 | Fort Baker Capital Management#3 · 1,371,923 sh | 1,371,923 | $14.4M | 1.06% | New |
| 4 | D. E. Shaw#4 · 1,426,000 sh | 1,426,000 | $12.9M | <0.01% | 0.0% |
| 5 | Decagon Asset Management LLP#5 · 1,269,131 sh | 1,269,131 | $10.8M | 2.06% | New |
| 6 | LINDEN ADVISORS#6 · 1,352,411 sh | 1,352,411 | $10.2M | 0.05% | -27.3% |
| 7 | Ghisallo Capital Management#7 · 800,000 sh | 800,000 | $8.6M | 0.17% | 0.0% |
| 8 | TWO SIGMA INVESTMENTS#8 · 725,000 sh | 725,000 | $7.8M | <0.01% | 0.0% |
| 9 | Hudson Bay Capital Management#9 · 739,994 sh | 739,994 | $7.6M | 0.02% | 0.0% |
| 10 | AQR Arbitrage#10 · 1,071,628 sh | 1,071,628 | $7.4M | 0.11% | -23.4% |
| 11 | Shay Capital#11 · 623,687 sh | 623,687 | $6.7M | 0.43% | New |
| 12 | Governors Lane#12 · 604,857 sh | 604,857 | $6.5M | 0.54% | -36.8% |
| 13 | LMR Partners LLP#13 · 1,092,679 sh | 1,092,679 | $6.5M | 0.02% | -14.3% |
| 14 | K2 PRINCIPAL FUND, L.P.#14 · 806,945 sh | 806,945 | $6.3M | 0.46% | +146.2% |
| 15 | Sculptor Capital#15 · 702,819 sh | 702,819 | $6.3M | 0.05% | +17.0% |
| 16 | MOORE CAPITAL MANAGEMENT#16 · 675,000 sh | 675,000 | $5.3M | 0.08% | 0.0% |
| 17 | Radcliffe Capital Management, L.P.#17 · 478,061 sh | 478,061 | $5.2M | 0.39% | -27.7% |
| 18 | Alberta Investment Management#18 · 775,000 sh | 775,000 | $5.1M | 0.03% | -31.1% |
| 19 | Harraden Circle Investments#19 · 1,366,261 sh | 1,366,261 | $5.0M | 0.64% | -15.1% |
| 20 | ARISTEIA CAPITAL, L.L.C.#20 · 988,491 sh | 988,491 | $3.9M | 0.05% | +163.6% |
| 21 | FNY Investment Advisers#21 · 327,200 sh | 327,200 | $3.5M | — | New |
| 22 | Mint Tower Capital Management B.V.#22 · 430,000 sh | 430,000 | $3.5M | 0.40% | -4.4% |
| 23 | WHITEBOX ADVISORS#23 · 375,000 sh | 375,000 | $3.0M | 0.04% | 0.0% |
| 24 | CITADEL ADVISORS#24 · 250,266 sh | 250,266 | $2.7M | <0.01% | +2311.7% |
| 25 | DLD Asset Management#25 · 264,853 sh | 264,853 | $2.3M | 0.15% | +5.9% |
| 26 | GOLDMAN SACHS GROUP#26 · 205,090 sh | 205,090 | $2.2M | <0.01% | -37.4% |
| 27 | L1 Global Manager Pty Ltd#27 · 200,000 sh | 200,000 | $2.2M | 1.52% | 0.0% |
| 28 | Jain Global#28 · 185,108 sh | 185,108 | $2.0M | <0.01% | -63.0% |
| 29 | PERISCOPE CAPITAL#29 · 215,000 sh | 215,000 | $2.0M | 0.17% | -61.0% |
| 30 | SkyView Investment Advisors#30 · 182,495 sh | 182,495 | $2.0M | 1.54% | New |
| 31 | Verition Fund Management#31 · 140,797 sh | 140,797 | $1.5M | <0.01% | -55.8% |
| 32 | MMCAP International SPC#32 · 187,500 sh | 187,500 | $1.5M | 0.13% | 0.0% |
| 33 | TUDOR INVESTMENT ET AL#33 · 123,842 sh | 123,842 | $1.3M | <0.01% | New |
| 34 | Shaolin Capital Management#34 · 257,811 sh | 257,811 | $1.2M | 0.06% | -66.6% |
| 35 | HEALTHCARE OF ONTARIO PENSION PLAN FUND#35 · 500,000 sh | 500,000 | $1.1M | <0.01% | 0.0% |
| 36 | CANTOR FITZGERALD, L. P.#36 · 88,283 sh | 88,283 | $951.7K | 0.01% | New |
| 37 | TORONTO DOMINION BANK#37 · 82,550 sh | 82,550 | $889.9K | <0.01% | -93.1% |
| 38 | Baird Financial Group#38 · 78,500 sh | 78,500 | $846.2K | <0.01% | 0.0% |
| 39 | MILLENNIUM MANAGEMENT#39 · 69,384 sh | 69,384 | $748.0K | <0.01% | -77.5% |
| 40 | BNP PARIBAS FINANCIAL MARKETS#40 · 185,717 sh | 185,717 | $611.1K | <0.01% | -7.0% |
| 41 | Schonfeld Strategic Advisors#41 · 80,000 sh | 80,000 | $604.7K | <0.01% | -68.7% |
| 42 | JPMORGAN CHASE#42 · 49,000 sh | 49,000 | $587.5K | 0.00% | -2.0% |
| 43 | Clear Street Group#43 · 99,164 sh | 99,164 | $570.7K | <0.01% | -58.9% |
| 44 | GLAZER CAPITAL#44 · 50,100 sh | 50,100 | $540.0K | 0.01% | -93.5% |
| 45 | JANE STREET GROUP#45 · 45,049 sh | 45,049 | $533.4K | 0.00% | -2.2% |
| 46 | HRT FINANCIAL#46 · 47,190 sh | 47,190 | $508.0K | <0.01% | New |
| 47 | CSS#47 · 151,718 sh | 151,718 | $332.2K | 0.01% | -72.1% |
| 48 | RIVERNORTH CAPITAL MANAGEMENT#48 · 224,942 sh | 224,942 | $323.9K | 0.02% | -65.5% |
| 49 | MIZUHO SECURITIES USA#49 · 19,469 sh | 19,469 | $202.5K | <0.01% | 0.0% |
| 50 | HIGHBRIDGE CAPITAL MANAGEMENT#50 · 17,606 sh | 17,606 | $189.4K | <0.01% | +74.2% |
| 51 | Alpine Global Management#51 · 71,039 sh | 71,039 | $155.6K | 0.03% | New |
| 52 | READYSTATE ASSET MANAGEMENT#52 · 12,528 sh | 12,528 | $135.1K | <0.01% | -92.8% |
| 53 | GEODE CAPITAL MANAGEMENT#53 · 11,102 sh | 11,102 | $119.7K | 0.00% | 0.0% |
| 54 | SUSQUEHANNA INTERNATIONAL GROUP, LLP#54 · 48,825 sh | 48,825 | $106.4K | 0.00% | New |
| 55 | EverSource Wealth Advisors#55 · 8,500 sh | 8,500 | $91.6K | <0.01% | New |
| 56 | Lineage Point Capital#56 · 35,771 sh | 35,771 | $78.3K | 0.02% | -80.5% |
| 57 | Centiva Capital#57 · 31,450 sh | 31,450 | $68.6K | <0.01% | -89.0% |
| 58 | UBS Group AG#58 · 3,810 sh | 3,810 | $43.1K | 0.00% | -28.0% |
| 59 | Thomas J. Herzfeld Advisors#59 · 5,000 sh | 5,000 | $10.9K | <0.01% | New |
| 60 | MORGAN STANLEY#60 · 35 sh | 35 | $377.00 | 0.00% | -43.5% |
| 61 | Caitong International Asset Management , Ltd#61 · 4 sh | 4 | $43.00 | 0.00% | New |
Funds that sold out of ATII in Q2 2026 (12)
Held ATII at the end of Q1 2026 and filed a Q2 2026 13F without it. Not in the list above, because they no longer hold it. Largest prior position first.
| Institution | Shares sold | Value in Q1 2026 |
|---|---|---|
| Westchester Capital Management1,107,143 sh | 1,107,143 | $9.5M |
| PICTON MAHONEY ASSET MANAGEMENT625,000 sh | 625,000 | $5.3M |
| RLH Capital448,289 sh | 448,289 | $4.2M |
| COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS400,000 sh | 400,000 | $4.2M |
| J. Goldman369,778 sh | 369,778 | $3.8M |
| METEORA CAPITAL295,612 sh | 295,612 | $3.1M |
| Quarry308,691 sh | 308,691 | $3.0M |
| BERKLEY W R208,065 sh | 208,065 | $2.2M |
| O'Connor Alternative Investments200,000 sh | 200,000 | $2.1M |
| WOLVERINE ASSET MANAGEMENT134,280 sh | 134,280 | $1.4M |
| GRITSTONE ASSET MANAGEMENT148,621 sh | 148,621 | $1.1M |
| Virtu Financial53,686 sh | 53,686 | $561.0K |
Source: Form 13F-HR filings on SEC EDGAR, Q2 2026. Values are as reported by each manager at quarter end. “% of portfolio” is the position’s share of the manager’s total reported 13F value for the same quarter. “New” means the manager filed a 13F for Q1 2026 without this position; a dash means no comparison is available. Where a manager’s own filing is internally inconsistent its value is withheld and it is listed last. 13F data shows reported holdings, not recommendations.