The Financial Select Sector SPDR ETF (ticker XLF) has had the biggest inflow of assets among nine industry SPDR ETFs in the past week, month and three months, according to Asbury Research.
"We're likely to see outperformance," said Asbury's chief strategist, John Kosar, who has been running a model using the SPDR ETFs for several years. Rarely has a sector ETF performed best in all three categories and, interestingly, industrials has seen the most outflows for each of the same time frames, also unusual. The XLF is up 2.5 percent in the past three months, while the S&P 500 is up 0.4 percent in the same period.
"If we get horrible earnings or something happens, or interest rates dive back down to 2 percent, or there's something that upsets the banks, it's going to be everybody out of the pool, and you're going to see it reflected in this table," Kosar said.
Read MoreChina's market looks like the Dow in 1929: Top technician
Stocks bounded higher on relatively light volume Monday, after Greek authorities agreed to austerity measures that will be voted on by that country's parliament Wednesday.
"I'm just not sure that we are there. Basically, this is obviously another 'kick the can,'" said O'Rourke. The Dow rose 217 to 17,977, and the S&P 500 was up 22 at 2,099.
"Even though we're up today. ... It doesn't seem like people are really enthused about Greece. I think people are covering shorts and were caught out of position, and I'm not sure people are going to jump back in tomorrow," he said.
Yields moved higher on the Greek headlines, but were off the highs late in the day. The 10-year was yielding 2.43 percent, after reaching 2.47 percent earlier.
Read MoreSorry, but Grexit chance is still 'significant'
As for economic data, the retail sales number will be key and markets will focus on what it says about the consumer. The June headline sales number is expected to be up 0.3 percent, compared with a 1.2 percent gain in May. Core sales, excluding autos, gasoline and building materials are expected to be up 0.5 percent, compared with a 1 percent gain last month, according to Thomson Reuters.
"I think it should be another solid report, though not as stellar as last month," said Moody's Analytics' chief economist, Mark Zandi. "More broadly, it signals that consumers are picking up. They're starting to spend more aggressively, and I would expect more of that going forward."
Zandi said the improving jobs market and wages have helped. "There's nothing but tail winds behind the consumer," he said, noting debt loads are lower as well.
Besides bank earnings, Yum Brands and CSX also report, after the closing bell. There is also a speech Tuesday evening from Kansas City Fed President Esther George at 8:15 p.m. ET.
--Update - Corrects that industrials is the sector with the most outflows