 NEW YORK, April 16, 2021 PRNewswire -- OTC Markets Group Inc. OTCQX: OTCM, operator of financial markets for 11,000 U.S. and global securities, today announced Defiance Silver Corp. TSX-V: DEF; OTCQX: DNCVF, a Mexico-based silver, gold, copper, and polymetallic exploration development company, has qualified to trade on the OTCQX Best Market. Defiance Silver Corp.upgraded to OTCQX from the Pink market. 