* Futures up: Dow 30 pts, S&P 2.5 pts, Nasdaq 13.5 pts
By Sruthi Shankar
Aug 24 (Reuters) - U.S. stock index futures rose slightly on Thursday, with caution prevailing ahead of the start of the annual gathering of central bankers at Jackson Hole, Wyoming.
* Federal Reserve Chair Janet Yellen and European Central Bank President Mario Draghi are scheduled to speak on Friday, although the likelihood of new policy messages from either are slim.
* Nonetheless, their speeches will be perused for hints on the stand of each central banks, especially the Fed, on monetary policy and its path ahead.
* The Fed remains the only major central bank to have begun raising rates and it is also seeking to rationalize the huge stores of securities it has built while pumping cash into the economy in the past eight years.
* Central bankers' view on the global economy and monetary policy will be a change from the past two weeks, when the stock market has been roiled by concerns over geopolitics, mayhem in Washington and President Donald Trump's controversial comments.
* U.S. stocks closed lower on Wednesday as investors grappled with a threat from Trump to shut down the government if funds are not secured to build a Mexico border wall.
* The bond and currency markets also took a hit from Trump's comments, which came as a late-September deadline looms for U.S. officials to raise the debt ceiling or risk a default.
* Economic data due includes a report that is expected to show jobless claims increased last week, and another that is likely to show existing home sales rose in July. The reports are due at 8:30 a.m. ET (1230 GMT) and 10:00 a.m., respectively.
* Shares of Hormel Foods fell 4.16 percent to $32.51, while those of J.M. Smucker fell 3.74 percent to $114.40 after the packaged foods makers reported disappointing quarterly results and cut their full-year forecasts.
* Signet Jewelers surged nearly 17 percent to $60.50 after it reported better-than-expected results and said it would buy an online jeweler.
* Shares of Guess jumped 13.62 percent to $14.18 after the company reported better-than-expected quarterly profit and sales.
Futures snapshot at 6:58 a.m. ET:
* Dow e-minis were up 30 points, or 0.14 percent, with 18,030 contracts changing hands.
* S&P 500 e-minis were up 2.5 points, or 0.1 percent, with 126,323 contracts traded.
* Nasdaq 100 e-minis were up 13.5 points, or 0.23 percent, on volume of 27,396 contracts. (Reporting by Sruthi Shankar in Bengaluru; Editing by Savio D'Souza)