US stock futures add to gains; D.R. Horton reports

U.S. stock-index futures tallied modest gains on Tuesday, adding to Wall Street's record-breaking advance.

"The U.S. markets, in particular, are gunning for any reason to head higher," said Evan Lucas, market strategist at IG, in a morning note.

"I would be watching anything with U.S.-exposure, or that continues to return capital to shareholders, as being very attractive in the current environment."

Wall Street NYSE
Victor J. Blue | Bloomberg | Getty Images

D.R. Horton fell in early New York trading after the homebuilder reported better-than-expected quarterly revenue but fell short on earnings. Insys Therapeutics gained after the specialty drug developer reported quarterly results.

Read MoreEarly Movers: DHI, BABA, ZNGA, DRI, UAL & more

Earnings will heat up again on Wednesday, with results from Macy's and Cisco Systems. According to Deutsche Bank, of the roughly 420 companies that have reported so far in the U.S. this quarter, 80 percent have beaten earnings per share estimates and 60 percent have exceeded sales expectations.

European and Asian stocks were boosted in early trade on Tuesday by Wall Street's gains in the previous session, which saw the S&P 500 and the Dow end at all-time highs.

Read MoreFed's Plosser: Low rates 'should make us nervous'