$10,000 in Tesla When It Joined the S&P 500 Would Be About $15,700 Today. An Index Fund Would Have Done Better.

September 13, 2026 - 08:33

When Tesla joined the S&P 500 in December 2020, index funds were forced to buy the stock at a record price of $695 a share. Investors who put $10,000 into Tesla at that moment would have roughly $15,700 today. That sounds like a solid gain until you compare it with the boring alternative.

The same $10,000 placed in a plain S&P 500 index fund would be worth more now. The reason comes down to timing and valuation. Tesla entered the index after a massive run-up, which meant funds tracking the S&P 500 had to purchase shares near a peak. Passive investors had no choice. The rules of index inclusion required them to buy.

Tesla's stock has since experienced sharp swings. It climbed further in 2021, then fell hard in 2022, and has struggled to regain its former highs. Meanwhile, the broad market kept grinding higher, powered by other companies that did not carry the same extreme valuation.

The episode highlights a quiet risk of index investing. When a hot stock joins a major index, funds buy it regardless of price. Sometimes that works out. Sometimes it does not. In Tesla's case, the electric vehicle maker's index debut has so far lagged the simple, low-cost fund that tracks the very index it joined.