The current allocation of volume, open interest, and a lot more cotton futures information, can be found on the ICE futures website under “Featured Reports”. Volume (viewed above as the green line) is defined as the total daily number of contracts traded in a session. The level of volume is often used to gauge the strength of continuing or changing trends. Typical cotton daily volume bounces around between 10,000 and 25,000 contracts. The graph above shows numerous instances of volume spiking above 50,000 contracts in the last several years. For the week ending Thursday October 12, ICE cotton saw average volumes between 15,436 contracts (on October 11) to 28,774 contracts (on October 12, the day of the WASDE report release). On October 12 about 63% of the volume was concentrated in the most active Dec’17 contract, with another 30% in the Mar’18.
Open interest (the red line above) refers to the number of active positions at the end of the day (not double counting both the buyer and seller). The pattern of open interest is somewhat similar to volume, except that it continues to shift from the front month. Open interest by contract has a similar pattern to volume in that the Dec’17 had 54% of the total while the Mar’18 had 32%, circa October 12. Open interest does not fluctuate as much as daily volume, but there are patterns where sharp surges or declines in open interest are associated with sudden rallies or sell-offs (often accompanied by spikes in volume). For the week ending October 12, the level of open interest was fairly static, as was the pattern of futures price settlement.