NEW YORK, May 08, 2025 (GLOBE NEWSWIRE) -- OTC Markets Group Inc. (OTCQX: OTCM), operator of regulated markets for trading 12,000 U.S. and international securities, today announced Black Swan Graphene Inc. (“Black Swan”) (TSX-V: SWAN; OTCQX: BSWGF), a company focused on the large-scale production and commercialization of patented high-performance and low-cost graphene products, has qualified to trade on the OTCQX® Best Market. Black Swan upgraded to OTCQX from the OTCQB® Venture Market. Black Swan begins tr ...