Mark A. Smith Increases His Stake in NioCorp by 2.5 Million Shares

CENTENNIAL, COLORADO--(Marketwired - Jun 4, 2015) - NioCorp Developments Ltd. ("NioCorp or the "Company") (TSX:NB)(OTCQX:NIOBF)(FRANKFURT:BR3), today announced that on June 1, 2015, its President and CEO, Mark A. Smith acquired an additional 2.5 million common shares of NioCorp stock through an exercise of previously granted options.

Mr. Smith, the Company's largest shareowner, increased his holdings in NioCorp to just over 17.9 million shares. This acquisition brings his holdings to 11.8 percent of total outstanding shares, on an undiluted basis.

"This share acquisition represents both my continued belief in NioCorp's mission and continued support of our efforts with the Elk Creek project," said Mr. Smith. "We have received positive feedback from the Elk Creek, Nebraska community, our prospective customers, and the investment community, without whom the continued success of this project could not be achieved."

About NioCorp:

NioCorp is a mineral development company pursuing high-quality natural resources. The Company's main focus is the Elk Creek Niobium Project, which is an advanced niobium exploration initiative located in southeast Nebraska. This resource is used to produce High Strength, Low Alloy ("HSLA") steel, which is a lighter, stronger steel used in automotive, structural, and pipeline applications.

Special note about forward-looking statements:

Neither TSX nor its Regulation Services Provider (as that term is defined in the policies of the TSX) accepts responsibility for the adequacy or accuracy of this release.

Certain statements contained in this press release may constitute forward-looking statements. Such forward-looking statements are based upon NioCorp's reasonable expectations and business plan at the date hereof, which are subject to change depending on economic, political and competitive circumstances and contingencies. Readers are cautioned that such forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause a change in such assumptions and the actual outcomes and estimates to be materially different from those estimated or anticipated future results, achievements or position expressed or implied by those forward-looking statements. Risks, uncertainties and other factors that could cause NioCorp's plans or prospects to change include changes in demand for and price of commodities (such as fuel and electricity) and currencies; changes or disruptions in the securities markets; legislative, political or economic developments; the need to obtain permits and comply with laws and regulations and other regulatory requirements; the possibility that actual results of work may differ from projections/expectations or may not realize the perceived potential of NioCorp's projects; risks of accidents, equipment breakdowns and labour disputes or other unanticipated difficulties or interruptions; the possibility of cost overruns or unanticipated expenses in development programs; operating or technical difficulties in connection with exploration, mining or development activities; the speculative nature of mineral exploration and development, including the risks of diminishing quantities of grades of reserves and resources; and the risks involved in the exploration, development and mining business. NioCorp disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise. Readers are advised that the Elk Creek PEA is preliminary in nature and includes Inferred Mineral Resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as Mineral Reserves. There is no certainty that the preliminary economic assessment will be realized. Mineral Resources are not Mineral Reserves because they do not have demonstrated economic viability. There is no guarantee that Inferred Mineral Resources will be converted to the Measured and Indicated Mineral Resource categories and, therefore, there is no guarantee that the project economics described herein will be achieved.

Contact

Teresa McGowan
Senior Manager of Investor Relations
720-639-4650
info@NioCorp.com
www.NioCorp.com