How Tesla's inclusion will impact the S&P 500's performance and valuation, according to Goldman

A Tesla car in London.
SOPA Images | LightRocket | Getty Images

(This story is for CNBC PRO subscribers only.)

After months of speculation, Tesla is finally joining the S&P 500 before trading begins on Monday. The company is the largest ever addition to the benchmark index based on market capitalization, leading investors to speculate about how the addition will impact the S&P, as well as the trillions of dollars that are benchmarked to it.

Crunching the numbers, Goldman Sachs looked at how Tesla will impact S&P metrics, including valuation and performance — and the results may take some investors by surprise.