Brodeski, however, isn't suggesting investors double down on U.S. stocks.
Like most financial advisors, he recommends that people stick to their financial plans and rebalance their portfolios to target allocations.
"I'm an admitted optimist, and I'm most optimistic where prices are most reasonable, and that's overseas," Brodeski said.
Mark Cortazzo, a CFP and senior partner at Macro Consulting Group, is more alarmed with the euphoria over U.S. stocks.
"People have stopped respecting risk," he said. "The memory of 2008 has disappeared from their minds."
Cortazzo is also pushing clients to rebalance their stock holdings toward cheaper foreign stocks. "At market tops and bottoms, people tend to do dumb things," he said. "They don't rebalance, because they don't want to buy losers."
With Europe looking fragile and emerging markets—most notably China—showing slower growth, it can be a tough sell. While admitting he could be wrong in the short term, Cortazzo is thinking about the next 10 years and advising clients to buy low and sell high with disciplined rebalancing.
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"The last time emerging markets were this out of favor versus the U.S. was 1999," he said. "If you bought emerging markets then, they went up four times between 2002 and 2007, while the U.S. market doubled."
David Grecsek, director of investment strategy and research for Aspiriant, thinks the U.S. market is at least fully valued and is telling clients to be "realistic" about returns going forward. He advises reducing exposure to small-cap stocks and investing in more defensive equities with high-quality names.
Grecsek also recommends rebalancing to lower-priced foreign markets and to fixed-income investments. "How many years in a row can we get double-digit gains in U.S. stocks?" he asked. "It can't continue forever. It's a good time to take risk off the table."