Over a long period of time that is what the market has returned. It is not guaranteed.One year it might be down 50% one year it might be 50%, but if you look at 30years S&P has returned about 7.5%. 10% is a just a round number makes math easier. You can plug in a different number my point its hard to get to 450 billion.
The S&P only had 500 companies starting in 1957 using that as the start date you get: 6.170%.
S&P has returned ~6.5% over the long term in inflation adjusted returns. However, the trend has been lower returns over time and inflation is currently very low. https://dqydj.com/sp-500-return-calculator/ (You can look at the methodology, but they project further into the past.)
6.736% : 1871 to now
6.525% : 1900 to now
6.281% : 1930 to now
5.977% : 1960 to now
Further, there is a lot of volatility in these numbers consider:
7.446% : 1990 to now
2.352% : 2000 to now
PS Stable companies reasonably have a premium associated with that stability.
Over a long period of time that is what the market has returned. It is not guaranteed.One year it might be down 50% one year it might be 50%, but if you look at 30years S&P has returned about 7.5%. 10% is a just a round number makes math easier. You can plug in a different number my point its hard to get to 450 billion.