Why do transactions show dividends for US500?

A dividend adjustment is applied to a share or index CFD position in the event of a dividend payment occurring in the underlying share or share constituent of an index. The ex-dividend date is the day a stock starts trading without its dividend payment. In the case of an index, an adjustment will be made that is equal to the number of points by which the index price must be adjusted downwards to take account of those shares in the index which go ex-dividend at the close of the cash market. The ex-dividend figure estimated by Bloomberg, rounded to the tick size we use for that index, is used to determine what adjustment to apply. In the case of long positions, the dividend adjustment is in the form a trading account credit. In the case of short positions, the dividend adjustment is in the form of a trading account debit.