Stock index futures briefly added to gains on Thursday after claims for unemployment benefits unexpectedly fell last week but trading was choppy as ECB chief Mario Draghi started a press conference and traders digested news of an austerity deal in Greece.

S&P 500 futures rose 1.9 points and were above 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 28 points, and Nasdaq 100 futures rose 4 points.