NEW YORK, Oct 21 (Reuters) - U.S. stock index futures held gains on Thursday after data showed a larger-than-forecast decline in first-time weekly applications for unemployment insurance.
S&P 500 futures rose 4.6 points and were above 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 gained 37 points and Nasdaq 100 futures added 10.75 points.
Futures rose earlier on strong corporate earnings, including Caterpillar's, a weaker U.S. dollar and reassuring data from China.