The Russell, which is composed exclusively of small-cap stocks, rose more than 10.2 percent for the week, its best one-week performance since 2011. Small-cap stocks are those with a market cap between $300 million and $2 billion.
The Dow, meanwhile, was up nearly 5.4 percent for the week, also its best weekly gain since 2011. The S&P 500 and the Nasdaq composite also lagged the Russell for the week, as they posted gains of about 3.8 percent each.
Leading the Russell higher on Friday were shares of PTC Therapeutics, which soared 88.3 percent.
Russell 2000 this weekSource: FactSet
U.S. stocks posted a sharp rally this week on the back of Republican Donald Trump's surprise victory over Hillary Clinton, as investors considered the prospects of higher infrastructure spending and less regulation within the financial sector.
That said, Terry Sandven, chief equity strategist at U.S. Bank Wealth Management, said in a Friday note that uncertainty around Trump's presidency remains.
"One of investing's bedrock principles is that markets dislike uncertainty, and the Trump victory leaves investors with several unanswered policy questions. The election results are unlikely to have a material impact on total economic growth, but markets will be in more of a 'reactionary' mode than usual due to the need for policy clarity and priorities from the new administration," he said.
Small caps have also handily outperformed the Dow, S&P and Nasdaq for the year. The Russell 2000 is up 12.9 percent for 2016, while the Dow, S&P and Nasdaq were up almost 8.2 percent, 5.9 percent and nearly 4.6 percent, respectively.