GREY CLOAK TECH INC (GRCK: Pink Current) | Tier Change Sat, Aug 15, 2020 12:00 - GREY CLOAK TECH INC ( GRCK : Pink Current) - Tier Change - The symbol, GRCK, no longer is classified as Pink No Information. As of Sat, Aug 15, 2020, GRCK resides in the Pink Current tier. You may find a complete list of tier changes at otcmarkets.com .