Trader NYSE green
Traders work on the floor of the New York Stock Exchange shortly after the opening bell in New York, U.S., March 17, 2020.
Lucas Jackson/Reuters
  • The S&P Completion Index tracks every US stock that’s not included in the S&P 500. It its up nearly 33% in 2020, more than double the benchmark’s 14% gain. 
  • The completion index is typically associated with small and mid-cap stocks, but until this week, it counted one very high profile company among its top constituents: Tesla. 
  • Tesla’s 665% gain in 2020 likely drove the completion index’s ride upwards, according to a report in The Wall Street Journal.
  • Visit Business Insider’s homepage for more stories.

A stock index that tracks all US stocks except those in the S&P 500 has returned more than double what the benchmark index earned this year.

The index, called the S&P Completion Index, is up nearly 33% this year, compared to a 14% gain for the S&P 500 during the same time period. 

The completion index is typically associated with small and mid cap stocks that don’t make it into the S&P 500. But one very high profile company was, until recently, counted among the constituents of the S&P Completion Index: Tesla.

Read more:From getting laid off to making six figures a year: How a single mom built a rental portfolio and started a house-flipping business with just $8,000 in savings

Before the electric vehicle maker joined the S&P 500 on Monday, it was the darling of the completion index. Its 665% gain in 2020 likely drove the index’s gains, according to a report in The Wall Street Journal.

The S&P Completion Index is up 2% since the beginning of this week. Meanwhile, the S&P 500 has stayed relatively flat in that same time period.

The completion index is also home to other 2020 star performers, including Zoom (up over 460% YTD), Square (up 272% YTD), and Moderna (up over 560% YTD). In total the index tracks 3,231 constituents, according to S&P Global.

Read the original article on Business Insider