The Dow and aren't the only ones to post a record week to start the year. Global markets like Japan's Nikkei and the German DAX also had strong starts to 2018.

Some market watchers see opportunities abroad as equity valuations in the U.S. appear historically stretched.



The emerging markets ETF, the EEM, just posted its longest daily winning streak since August 2016, rising for seven-straight sessions and seeing its fifth-consecutive week of gains.



The Nikkei on Friday rallied to its highest level since 1991. The DAX traded a mere 1.5 percent below its all-time high level, and Russia's RTS index turned in its best week in a little over a year.



So, where should investors turn if they are considering foreign markets?



German equities look particularly attractive relative to the U.S., said Boris Schlossberg, managing director of foreign exchange strategy at BK Asset Management. The DAX, which just posted its best year since 2013, has risen 3 percent in the first week of trading in 2018.



"From a fundamental point of view, there's a lot more value overseas right now. I think the trade of 2018 is going to be long DAX, short Dow, as you're going to see underperformance in the U.S. and overperformance in Europe, and perhaps even in Japan," Schlossberg said Friday on CNBC's "Trading Nation."



To be sure, Schlossberg doesn't necessarily see massive downside for the U.S. this year, but he sees better opportunity from a valuation perspective in European markets.



Commodity-exposed countries are also attractive, said Larry McDonald, publisher of the Bear Traps Report.



"Commodities are the cheapest to U.S. equities than at any point in the last 30 years, and we're seeing a secular shift in commodities right now. And that shift is now taking place through higher yields; in Indian yields, for example," McDonald said Friday on "Trading Nation," referring to India's 10-year bond yield.



Russia, too, is where investors will see "a tremendous catch-up in outperformance relative to the U.S.," McDonald said.