* Dow, S&P 500 coming off record closing highs
* Surge of holiday packages delays UPS shipments
* Hackers of Target also stole encrypted PINs -sources
* Futures up: Dow 62 pts, S&P 2.6 pts, Nasdaq 6.25 pts
By Ryan Vlastelica
NEW YORK, Dec 26 (Reuters) - U.S. stock index futures edged higher on Thursday, suggesting the market's recent upside momentum would continue, though trading was expected to be light following the Christmas holiday.
* This is the first day of full trading since Monday, following an early close on Tuesday and a holiday closure on Wednesday. Volume has been anemic all week, with many market participants out of the office, and that light action could amplify market volatility.
* United Parcel Service will be in focus a day after the shipping company said poor weather and a high volume of holiday packages delayed the arrival of Christmas presents around the world.
* Amazon.com Inc offered compensation to affected customers with shipping refunds and $20 gift cards.
* In another black eye for the retail industry, the hackers who attacked Target Corp and compromised up to 40 million credit cards and debit cards also managed to steal encrypted personal identification numbers, a senior payments executive told Reuters.
* Despite that, markets appeared to have an upward bias, with the Dow pointing to a sixth straight day of gains, its longest winning streak since March.
* S&P 500 futures rose 2.6 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 added 62 points and Nasdaq 100 futures rose 6.25 points.
* Both the Dow and S&P 500 closed at record highs on Tuesday. However, further upside may be limited at these levels, especially in the absence of major trading catalysts.
* The S&P 500 has soared 28.5 percent this year, largely due to stimulus measures from the U.S. Federal Reserve. The index is on track for its best year since 1997. The Dow is up 24.8 percent in 2013 while the Nasdaq has jumped 37.6 percent for the year.
* Japan's SoftBank Corp was in talks to acquire U.S. wireless carrier T-Mobile US Inc and was discussing funding for a deal with financial institutions, sources close to the matter told Reuters.