Positive market momentum should last as long as economic data remains strong, strategist Erik Ristuben told CNBC on Friday.
However, the market rally is late in the cycle, he pointed out.
"Late-cycle investing, as you know, is picking up dollars in front of the steamroller, and it's a really good idea to keep an eye on the steamroller — which we don't think is imminent but we think it's not that far away," the chief investment strategist at Russell Investments said in an interview with "Closing Bell."
Therefore, he thinks investors should consider diversifying their assets with such things as real-estate trusts and commodities.
Stocks have rebounded sharply from last week's correction. On Feb. 8, the major averages closed 10 percent below all-time highs set last month.
On Friday, equities closed higher, extending their winning streak to six days in a row. The S&P 500 had its best week since January 2013, while the Nasdaq had its best week since December 2011. The Dow Jones industrial average saw its biggest weekly gain since November 2016.
The major averages were still down for February.