If you expect either 7% real returns or 10% nominal returns from the stock markets over the next few decades, you're gonna have a bad time - mostly because real interest rates in the 21st century are much lower than in the second half of the 20th.
Current expert thinking is that there is a 4% equity risk premium over cash interest rates. Current cash rates are 1% nominal or -1% real. If you are an optimist like the Fed, cash rates will rise to 3% over the long term - which gets you to 7% nominal/5% real at best.
I wasn't making a prediction on future returns just commenting on the historical returns used. For this case 5-7% should be more than enough as a comparison to the Tesla investment anyway. I'm curious about those risk premium estimates though. Any pointers or sources on where to read more about them?
Current expert thinking is that there is a 4% equity risk premium over cash interest rates. Current cash rates are 1% nominal or -1% real. If you are an optimist like the Fed, cash rates will rise to 3% over the long term - which gets you to 7% nominal/5% real at best.