The indices now include larger tilts toward technology, which makes sense given how we are living today. Lystra argued that the indices reflect how more people are utilizing the services and products of these tech companies, like Google search and Amazon’s Prime shipping.

“It reflects how the economy has transitioned to something tech focused,” Lystra said.

IWB’s largest sector component is information technology at 21.6% of the underlying portfolio, with Apple (NasdaqGS: AAPL), Microsoft (NasdaqGS: MSFT) and Amazon among its top three holdings. IWM also includes a hefty 17.9% tilt toward information technology names, including Advanced Micro Devices and Take Two Interactive Software among its top components.

“It looks like we could be in for another style shift, as value stocks have recently made a comeback compared to growth stocks,” Steven DeSanctis, SMID Cap Strategist, Jefferies & Co., said in a note. “However, [small cap]growth stocks still tend to trade at lower price-to-earnings multiples [relative to their historical average]than [small cap]value stocks while [tending to deliver higher]relative earnings growth than their value counterparts. With that said, buckle up because the ride could be bumpy.”

Overall, FTSE Russell Indexes’ rebalancing act went on without a hitch, especially compared to last year when we were experiencing a number of volatile events that caused markets to rapidly shift.

For more information on index ETFs, visit our indexing category.