JATT II Acquisition Corp Announces Closing of $60,000,000 Initial Public Offering

WESTFIELD, N.J., April 20, 2026 — JATT II Acquisition Corp (the “Company”) announced the closing of its initial public offering of 6,000,000 ordinary shares at an offering price of $10.00 per ordinary share on April 20, 2026. Total gross proceeds from the offering were $60,000,000 before deducting underwriting discounts and commissions and other offering expenses payable by the Company.

The ordinary shares began trading on the Nasdaq Global Market (“NASDAQ”) under the ticker symbol “JATT” on April 17, 2026.

Guggenheim Securities, LLC is acting as sole book-running manager. The Company has granted the underwriters a 45-day option to purchase up to 900,000 additional ordinary shares at the initial public offering price to cover over-allotments, if any.

A registration statement relating to the securities sold in the initial public offering was declared effective by the U.S. Securities and Exchange Commission (the “SEC”) on April 16, 2026. The public offering is being made only by means of a prospectus. Copies of the prospectus relating to the offering may be obtained from Guggenheim Securities, LLC, Attn: Equity Syndicate Department, 330 Madison Avenue, 8th Floor, New York, NY 10017, by telephone at (212) 518-9544, or by email at [email protected].

This press release shall not constitute an offer to sell or a solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About JATT II Acquisition Corp

JATT II Acquisition Corp is a newly incorporated blank check company incorporated as a Cayman Islands exempted company and formed for the purpose of entering into a merger, amalgamation, share exchange, asset acquisition, share purchase, recapitalization, reorganization or similar business combination with one or more businesses. The Company has not selected any specific business combination target and has not, nor has anyone on its behalf, engaged in any substantive discussions, directly or indirectly, with any business combination target with respect to an initial business combination with the Company. While the Company may pursue an initial business combination in any business or industry, the Company intends to focus its search on healthcare and healthcare-related businesses, with a primary emphasis on biotechnology and broader life sciences. In particular, the Company intends to seek businesses that can benefit from the clinical, scientific, operational, strategic and capital markets experience of the management team and board of directors and, in many cases, from access to the public markets as a means of funding continued development, executing strategic transactions and increasing visibility with investors and potential partners. The Company expects to focus particularly, though not exclusively, on businesses applying data-driven approaches, including machine learning, computational biology, structure-based drug design and related technologies, to improve the therapeutic discovery and development process. The Company is sponsored by JATT Ventures II L.P. and is led by Dr. Someit Sidhu, Chief Executive Officer and Chairman of the Board, and Nicholas Fernandez, Chief Financial Officer. The Company’s Board of Directors also includes Verender S. Badial, Arjun Goyal, Jonathon Kluft and Christopher Staral, bringing extensive experience across biotechnology investing, company architecture, and public and private capital markets. Learn more at www.jattacquisition.com.

Contacts

Nicholas Fernandez Chief Financial Officer 153 Central Avenue C/O 56 Westfield, NJ 07091 201-688-0364