All major indices quoted have a futures market related to them. This future trades at a price which reflects the underlying market plus some adjustments. These adjustments are calculated from the theoretical value of dividends payable between today and the expiry of the future AND the cost of carry for the index over the same period. This adjustment is called the ‘Fair Value’. A spread betting provider will link the Rolling Daily Cash quote to the relevant future concerned and offset the quote by the current Fair Value. Therefore, the Rolling Daily price is moved by the futures contract price and not vice versa. This is because the underlying cash price is a lagging market indicator which does not react in a timely manner to market-moving news.