Interesting tidbit, but a little "inside baseball". TSLA gets added to the S&P on Dec 21 in essentially one transaction. The market seems to be ignoring the dynamics of this change. TSLA's PE is over 1,000 so at a 1% position it is going to push the total S&P trailing P/E over 30x and the forward P/E over 27x. For a comparison in "expensive" we have to go back to the DotCom bubble. Also interesting, maybe even more so, is the impact on S&P 500 implied Vol. (option pricing factor) TSLA is over 90, while S&P Vix is now 21.5. Options traders had actually made the Dec 18 expiration LOWER than the Dec 31 expiration (after TSLA is added). This demonstrates how markets are super confusing - but they will fix themselves. so beware. I suspect when they fix themselves the reason won't make any more sense than it does now to financial media. We might see TSLA's add as the turning point to a correction. I'm a little wary of any Santa Clause rally as some of the people pushing the option mispricing don't yet get the concept of taxes in these transactions.