Public traders buy or sell a certain number of standard contracts.
Buying and opening positions: refers to the trading means adopted by investors to be bullish on future price trends. Buying and holding a bullish contract means that the account funds buy the contract and freeze it.
Selling and opening positions: refers to the trading means adopted by investors to bearish on future price trends and sell bearish contracts. Selling and opening positions, account funds are frozen.
Tea opening refers to the contract for investors to buy and sell tea.