These two letters can represent many things. The stock code of China Minsheng Bank Co., Ltd. is CMAKY. I wonder if it is the bank you are looking for.
China Minsheng bank co., ltd., approved by the State Council guohan [1995] No.32 and China people's bank yinfu [1996] 14, is established by the all-China Federation of industry and commerce, Guangzhou Yitong group company, China township enterprise investment and development co., ltd., China national coal industry import and export corporation, China shipowners mutual insurance association, Shandong pan. China Minsheng Bank Co., Ltd. was incorporated on February 7, 1996 with a registered capital of1380,248,000 yuan.