U.S. stocks are lower on Monday after a three-day holiday break as investors keep an eye out for more trade-related developments.

The Nasdaq composite inched fractionally higher in Tuesday's session. The S&P 500 shed less than 0.1%. Small caps led the market, with the Russell 2000 index climbing nearly 0.7%. The Russell recouped about half of Monday's drop of nearly 1.6%.

When it comes to this president, his trade war, the economy, financial markets and uncertainty, "known unknowns" are better than "unknown unknowns."