U.S. stock index futures turned negative on Thursday after data showed first-time applications for unemployment insurance unexpectedly rose in the latest week.

S&P 500 futures fell 1.5 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures lost 12 points and Nasdaq 100 futures fell 1 point.