Stock index futures added to losses on Thursday after data showed initial jobless claims rose more than expected last week.

S&P 500 futures fell 3.3 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration of the contract. Dow Jones industrial average futures added 8 points and Nasdaq 100 futures shed 7.5 points.

(Reporting by Chuck Mikolajczak; Editing by Bernadette Baum)