Money 2.0 Stuff: Is it really Open Finance if traders aren’t banging the close?

"A manipulative or disruptive trading practice whereby a trader buys or sells a large number of futures contracts during the closing period of a futures contract (that is, the period during which the futures settlement price is determined) in order to benefit an even larger position in an option, swap, or other derivative that is cash settled based on the futures settlement price on that day."

The basic idea is that there is money to be made if the cost to manipulate an underlying index is lower than the profit to be made from derivative contracts based on that index. This happens regularly enough that the CFTC has a definition of ‘banging the close’ on its website, although there are precautionary measures that can be levied to prevent widespread manipulation: derivative exchanges usually place a cap on the number of contracts an individual account can hold and the CFTC regularly surveils market activity, punishing investors that have been deemed to engage in illegal behaviour.