Futures Market

In the futures markets, there is no assurance that a liquid market may exist for offsetting a commodity contract at all times. Some future contracts and specific delivery months tend to have increasingly more trading activity and have higher liquidity than others. The most useful indicators of liquidity for these contracts are the trading volume and open interest.
There is also dark liquidity, referring to transactions that occur off-exchange and are therefore not visible to investors until after the transaction is complete. It does not contribute to public price discovery

Overview
The most liquid futures contracts and markets are those with which, and within which, you can enter and exit a trade almost immediately.
Some of the main advantages of trading in highly liquid futures markets are:
- Exceptionally rapid fills of your entry and exit orders
- Extremely advantageous entry and exit price points

The main benefit of course is extracting optimum profit potential should the trade move in your favor.
In these highly liquid futures markets, there are a very large number contracts being continuously traded, providing willing buyers and sellers to enter into a trade with your desired long or short position.

What is Liquidity?
There are a couple of related definitions. Overall, a high level of trading and "open interest" characterizes liquidity.
It is basically your ability to take an asset and quickly converting it into cash...or in our case, buying or selling specific commodity futures (or options) contract in the market, with little to no effect on your desired contract entry or exit price.
High liquidity allows for little to no effect on the desired entry price point into, or desired exit price point from a futures contract and market.
Whereas a commodity affected by low liquidity or trading activity can mean slow order fills and/or less desirable order entry and exit price points.

Some of the other most recognizable and most liquid futures