On the downside, energy (-0.7%) settled solidly lower as USA crude oil shed another 1.1% to $44.46/bbl, marking its worst level since November.
The CBOE Volatility Index (VIX - 10.37) fell 0.01 point, or 0.1%.
Amazon was up 0.8 percent, while Wal-Mart, Target and Kroger gained between 0.8 percent and 1.8 percent on Monday.
Consumer staples stocks, which were battered on Friday after Amazon.com's AMZN.O $13.7 billion deal to buy upscale grocer Whole Foods WFM.N , added to their losses.
"It looks like a bet that interest rates, such as the 10-year yield, are bottoming out", said Evans.
Yellen's confidence as her team raised interest rates for the third time in six months last week surprised investors who had expected more caution about the economy following a batch of weak US economic data. S&P 500 e-minis were up 7.25 points, or 0.3 percent, with 138,274 contracts traded. The widespread market gains were aided by the tech sector, with Amazon stock building off its recent momentum by shooting to an all-time high.
Advancing issues outnumbered declining ones on the NYSE by a 1.76-to-1 ratio; on Nasdaq, a 2.01-to-1 ratio favored advancers. The Dow and S&P 500 were on track to secure all-new highs by market close.