"Pancakes" refer to currencies such as Bitcoin, Ethereum, dogecoin, Litecoin, Bitcoin, Grapefruit Coin, etc. "Transaction liquidity" means that when the number of people trading is insufficient, the transaction is not real-time, but intermittent, and a smooth curve will not be displayed on the K-line, but an intermittent line. This is the lack of liquidity. Insufficient liquidity will generate liquidity risk in trading, that is, when you want to close your position, you can't close it at the right price, or even close it, causing losses. In futures, insufficient liquidity often appears in non-main contracts. Among the options, except for the top varieties, the number of participants in other options is not so sufficient and the liquidity is not high.