NioCorp Developments Ltd. (NASDAQ:NB), today announced the closing of its previously announced public offering in the United States. The Offering consisted of 20,000,000 common shares (or pre-funded warrants in lieu thereof) at a public offering price of $5.00 per common share (or $4.9999 per pre-funded warrant), for gross proceeds of approximately $100.0 million before deducting placement agent fees and offering expenses.

Maxim Group LLC acted as sole placement agent for the Offering.

NioCorp currently intends to use the net proceeds from the Offering for working capital and general corporate purposes, including to advance a critical minerals project in Southeast Nebraska and move it to commercial operation.

The Offering was made pursuant to an effective shelf registration statement on Form S-3ASR (File No. 333-290837), which was filed with the Securities and Exchange Commission and was automatically effective upon filing on October 10, 2025.

A final prospectus supplement and accompanying prospectus relating to the Offering and describing the terms thereof has been filed with the SEC and forms a part of the effective registration statement and is available on the SEC’s website at www.sec.gov. Copies of the final prospectus supplement and accompanying prospectus may be obtained by contacting Maxim Group LLC, at 300 Park Avenue, 16th Floor, New York, NY 10022, Attention: Syndicate Department, or by telephone at (212) 895-3745 or by email at syndicate@maximgrp.com. The final prospectus supplement filed with the SEC is also available on the Company’s profile on the SEDAR+ website at www.sedarplus.ca. No securities were offered or sold to Canadian purchasers under the Offering.

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

FOR MORE INFORMATION:

Jim Sims, Chief Communications Officer, NioCorp Developments Ltd., (720) 334-7066, jim.sims@niocorp.com

Alex Guthrie, Director, Investor Relations, NioCorp Developments Ltd., (647) 999-0527, aguthrie@niocorp.com

ABOUT NIOCORP

NioCorp is developing the Elk Creek Project that is expected to produce niobium, scandium, and titanium.  The Company also is evaluating the potential to produce several rare earths from the Elk Creek Project.  Niobium is used to produce specialty alloys as well as High Strength, Low Alloy steel, which is a lighter, stronger steel used in automotive, structural, and pipeline applications. Scandium is a specialty metal that can be combined with Aluminum to make alloys with increased strength and improved corrosion resistance. Scandium is also a critical component of advanced solid oxide fuel cells. Titanium is used in various lightweight alloys and is a key component of pigments used in paper, paint and plastics and is also used for aerospace applications, armor, and medical implants.  Magnetic rare earths, such as neodymium, praseodymium, terbium, and dysprosium are critical to the making of neodymium-iron-boron magnets, which are used across a wide variety of defense and civilian applications.