The Russell 2000 small-cap index hit an all-time high on Thursday and closed higher for its 10th consecutive session, only the second time it has enjoyed such a streak in the past decade.
The index is up nearly 13 percent in the past 10 sessions, versus the S&P 500's rise of 5 percent. And some say it is showing signs of momentum that could be sustained on a long-term basis, helping it to continue outperforming the large-cap sector.
"This Monday we saw 25 percent of the small caps make a 52-week high. Going back to 1995, that's the highest reading for one-day 52-week highs we've ever seen," Jonathan Krinsky, chief market technician at MKM Partners, said Thursday on CNBC's "Power Lunch." "So that type of breadth expansion tells us it's very broad-based and robust; that tends to continue momentum going forward."
And relative to the large-cap stock performance of the S&P 500, the Russell just this year has reversed its path, steadily rising since the beginning of 2016 after proving to be underperformers for the last three years.
"So we think, over the next six to 12 months, small-caps probably move higher, and they probably outperform the large caps, as well," Krinsky said.
Small-cap stocks' winning streak may be a result of Donald Trump's electoral win, said Dennis Davitt of Harvest Volatility Management.
Davitt said the recent "massive" move came about in the Russell 2000 thanks to speculation that Trump will scrap free-trade agreements.
This could be expected to hamper large companies that do a lot of exporting, and thus lead to small-cap outperformance — leading many investors to jump into the Russell 2000 in anticipation.