The Dow Jones industrial average was up 53 points, or 0.3 per cent, to 16,557 at midday Tuesday.
The Standard & Poor's 500 index rose six points, or 0.3 per cent, to 1,847 and the Nasdaq composite rose 17 points, or 0.4 per cent, to 4,171.
The S&P 500 is headed for its best year since 1997. The index is up 30 per cent in 2013, or 32 per cent with dividends included.
In the government bond market, the 10-year Treasury note continued to hover near the 3 per cent mark.
U.S. financial markets will be closed Wednesday for New Year's Day. Trading will reopen on Thursday.