JATT II ACQUISITION CORP JATT
ORD SHS · Common Stock · CUSIP G50765109
- SectorBlank check (SPAC)
- IndustryBlank Checks
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Shares outstanding: 8.0m as of 2026-05-28, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $11.36.
Biggest buyers
| Balyasny Asset Management L.P. | New | +500.0k |
| GREAT POINT PARTNERS LLC | New | +500.0k |
| RA CAPITAL MANAGEMENT, L.P. | New | +500.0k |
| Nantahala Capital Management, LLC | New | +450.0k |
| ADAR1 Capital Management, LLC | New | +417.7k |
| Atika Capital Management LLC | New | +400.0k |
| FRANKLIN RESOURCES INC | New | +400.0k |
| CITADEL ADVISORS LLC | New | +320.0k |
| BRAIDWELL LP | New | +250.0k |
| TCG Crossover Management, LLC | New | +200.0k |
Biggest sellers
| None |
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
JATT Ventures II L.P.
13D · may seek influence
no change · filed 2026-09-18
Stated purposeOn February 12, 2026, the Sponsor paid $25,000, or approximately $0.014 per share, to cover certain of the Issuer's offering costs in exchange for 1,725,000 Founder Shares (the "Founder Shares"), of which 225,000 founder shares were forfeited subject to the expiration of the underwriters' over-allotment option, pursuant to the Securities Subscription Agreement dated as of February 12, 2026 between the Sponsor and the Issuer (the "Founder Share Purchase Agreement"). On April 20, 2026, the Issuer consummated its initial public offering ("IPO") and in connection with the consummation, Sponsor purchased an aggregate of 300,000 private placement shares for an aggregate purchase price of $3,000,000. The reporting persons made the acquisitions reported in this Schedule 13D in support of the Issue… Full filing |
23.1% |
| RA CAPITAL MANAGEMENT, L.P. 13G · passive investor new · filed 2026-04-27 | 6.4% |
| GREAT POINT PARTNERS LLC 13G · passive investor -0.2 pts · filed 2026-08-14 | 6.2% |
| BALYASNY ASSET MANAGEMENT L.P. 13G · institution new · filed 2026-08-14 | 6.2% |
| Janus Henderson Group Ltd. 13G · institution new · filed 2026-08-13 | 6.2% |
| ADAR1 Capital Management, LLC 13G · institution new · filed 2026-08-14 | 5.4% |
| Atika Capital Management LLC 13G · institution new · filed 2026-08-14 | 5.1% |
Fell to 5% or below in the last year: Commodore Capital LP (0.0%, 2026-08-14)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 0 | — | 0 | — | — |
| Q2 2026 | 1 | — | 0 | — | — |
| Q3 2026 | 0 | — | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-04-20 | Sidhu Someit Chief Executive Officer, director · See Footnote | Bought | —300.0k shares |
| 2026-04-20 | JATT Ventures II L.P. 10% owner | Bought | —300.0k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| Balyasny Asset Management L.P. 0.01% of their portfolio | 500.0k $5.7m | New |
| GREAT POINT PARTNERS LLC 1.34% of their portfolio | 500.0k $5.7m | New |
| RA CAPITAL MANAGEMENT, L.P. 0.05% of their portfolio | 500.0k $5.7m | New |
| Jupiter Topco LLC 0.00% of their portfolio | 500.0k $5.7m | First filing |
| Nantahala Capital Management, LLC 0.15% of their portfolio | 450.0k $5.1m | New |
| ADAR1 Capital Management, LLC 0.22% of their portfolio | 417.7k $4.7m | New |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 400.0k $4.5m | New |
| Atika Capital Management LLC 0.45% of their portfolio | 400.0k $4.5m | New |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 320.0k $3.6m | New |
| FARALLON CAPITAL MANAGEMENT, L.L.C. 0.02% of their portfolio | 300.0k $3.4m | Not comparable |
| BRAIDWELL LP 0.11% of their portfolio | 250.0k $2.8m | New |
| Affinity Asset Advisors, LLC 0.11% of their portfolio | 200.0k $2.3m | New |
| TCG Crossover Management, LLC 0.05% of their portfolio | 200.0k $2.3m | New |
| Spruce Street Capital LP 0.36% of their portfolio | 160.0k $1.8m | New |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 159.7k $1.8m | New |
| Logos Global Management LP 0.05% of their portfolio | 100.0k $1.1m | New |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 96.2k $1.1m | New |
| TORONTO DOMINION BANK 0.00% of their portfolio | 50.5k $573.7k | New |
| Woodline Partners LP 0.00% of their portfolio | 50.0k $568.0k | New |
| Magnetar Financial LLC 0.00% of their portfolio | 47.9k $544.2k | New |
| 683 Capital Management, LLC 0.04% of their portfolio | 42.3k $480.1k | New |
| DIADEMA PARTNERS LP 0.04% of their portfolio | 9.0k $102.5k | New |
| Clear Street Group Inc. 0.00% of their portfolio | 7.1k $80.9k | New |
| Persistent Asset Partners Ltd 0.01% of their portfolio | 2.3k $26.1k | New |
| MORGAN STANLEY 0.00% of their portfolio | 8 $91 | New |