The mung bean contract of Zhengzhou Commodity Exchange, code GN, is mung bean in English. Most people who entered the futures industry late don't understand, because the mung bean contract gradually faded out after the large-scale forced liquidation storm in the summer of 1999. Although the contract standard still exists, no one participates in the transaction.

Prior to this, mung bean was the most active variety in domestic trading, and its market popularity far exceeded that of other domestic trading varieties.