There's an under-the-radar trend which could push stocks further into record territory, and it appears most of Wall Street doesn't even know about it.
"I think inflation will be the big surprise," said Joseph Zidle, portfolio strategist at Richard Bernstein Advisors on CNBC's "Trading Nation" this week.
His leading indicator: A tightening labor market that is driving up wages.
"This economy is really based on consumption, so it puts more money in the hands of consumers," he said, thus giving a boost to U.S. companies selling products and services.
Zidle referred to Commerce Department data showing the number of people voluntarily leaving their jobs, relative to the amount of people getting fired.
"More and more people are quitting their jobs right now," he observed. "In the law of large numbers, the only reason why people quit their jobs in big numbers is because they have something better lined up and something that pays more."
The scenario could help drive inflation to three to four percent, a number that's considered a sweet spot for companies' profits, explains Zidle.
"If we do start to see this inflation, I think it's very good for cyclicals because they have pricing powers — your energy, materials, tech, financials, small companies. I think it's very, very good for them," he said.
Although it isn't a situation that appears to be on the radar right now, that doesn't mean it couldn't soon surface as an issue.
The Fed has been taking a slow and steady approach to raising rates. The Wall Street consensus predicts the next quarter point interest rate hike will happen at the culmination of its next meeting on June 14.
However, the threat of rising prices could alter the Fed's deliberative approach.
"It could force the Fed's hand. The Fed historically tends to get behind the curve, and the economy tends to grow faster than what they're thinking," Zidle said. "It could cause the Fed to hike more aggressively than people think."