U.S. stocks were set for a flat and mixed open Tuesday morning following recent gains. Investors already have plenty of corporate earnings to digest from late Monday and early Tuesday, and the reports still keeping coming, including several heavyweights scheduled to post earnings today.

And as investors await Federal Reserve Chairman Ben Bernanke semiannual monetary-policy testimony to Congress at 10:00 a.m., they can read his opinion piece in the Wall Street Journal where he says the Fed will tighten, but not yet.

More here: Before the bell: Futures mixed after earnings, Bernanke's op-ed