U.S. stocks rallied on Tuesday to close up more than 1 percent higher in a second consecutive day of gains, boosted by a surge in oil prices and alleviation of concerns in the euro zone.
"We've got a continuation of strength. Looks like the two major drivers of yesterday's strength are still with us today," said Art Hogan, chief market strategist at Wunderlich Securities.
With Monday's and today's gains, the Dow, S&P and Nasdaq each regained about 70 percent or more of January losses.
The Dow Jones Industrial Average surged 305.3 points in the last 15 minutes of trade to close up 1.76 percent at 17,666.40. All blue chips advanced, led by Caterpillar's nearly 4 percent gain. Exxon Mobil and Chevron followed, each rising nearly 3 percent or more.
"With crude between $50 and $55, a lot of people are going to see Caterpillar as cheap," said Marc Chaikin, CEO of Chaikin Analytics.
Oil extended the past few days' gains to settle up $3.48, a 7 percent surge, to $53.05 a barrel, the highest settlement of 2015. WTI crude is up 22 percent from its intraday low of $43.58 last Thursday.
Encouraged, the Dow Transports closed up 1.46 percent, with only the airlines declining.
We're "obviously seeing a rebound in some of the oil sector," said Randy Frederick, managing director of trading and derivatives at Charles Schawb. "Overall the market has been weak, until late yesterday, so it'll be interesting to see if it holds up."
The Nasdaq underperformed the major indices, with Apple in the red for much of the day. Biotech declines also put pressure on the S&P.
Hogan was not concerned about the divergent performance. "You've got a consistently stabilizing energy market," he said. That "broader type move is more impactful on the Dow and the S&P than the Nasdaq."
The energy sector closed up 2.78 percent to lead advancers on the S&P 500 for 4 straight days of gains.
Firming oil prices and news out of Greece cheered U.S. markets into the close on Monday, putting the S&P 500 above 2,000 points in the close and the Dow up nearly 200 points.
The S&P closing above that key level is "significant," said Peter Cardillo, chief market economist at Rockwell Global Capital. "Perhaps it will set the stage for less volatility in the month of February and more tranquility as the ECB launches its quantitative easing program."
"This is a back and forth that's going to go on for a while," Frederick said. "The question is where it may go. We've got several weeks before we find out what happens."