"Even if you don't like Tesla and you think it's overvalued, the fact that it is going into the index would mean trillions of dollars would have some kind of position," said Jim Bianco, head of Bianco Research in Chicago. "As part of their benchmark, portfolio managers would not be able to ignore it."
Up 43% in just the past eight sessions, Tesla is among the most loved - and hated - stocks on Wall Street. It is the U.S. stock market's purest play bet on the rise of renewable energy and the decline of fossil fuels, and Tesla's Model 3 sedan has made major inroads among consumers.