Earlier quoted context omitted.
Wait, you're telling me he could have turned $1M into $3B just through investing in mutual funds?
Assuming a 10% return, which is about the max I could find for a single fund over 20 years, it'd take 84 years to turn $1M in to $3B. Conversely, plenty of funds do 15-20% in the short term. 15% only takes 57 years, and 20% brings it down to 44. So, doable, but you'd be considered a pretty amazing investor. And this all assumes the money was invested from the day he was born.
It's not uncommon for aggressive growth funds to take a 20% tumble in a year. Downside is much, much more destructive than many understand especially when one must also account for fund management fees (typically .7%) which are collected whether the fund gains or loses!
But the simple fact is that a 50% loss requires a 100% gain just to get back to even, which is still a loss once inflation and operating costs are factored in.
Here's a simple question that most people fail: Q: A mutual fund loses 50% in a year. In order to break even the next year, your fund must earn ? 1) inflation 2) 50% + inflation 3) 50% + your income tax rate 4) 100% + inflation 5) 100% + inflation + operating costs + 'it depends'
The correct answer is 5. The correct answer is nearly 106%- One must make up for actual loss (100%) PLUS operating expenses for both years (usually 0.7% per year: 1.5%), plus inflation for both years (2%/annum: 4%). Of course there are tax implication for gains/losses taken outside of a qualified retirement plan (401k,403b,etc.) and sheltering losses can complicate substantially, but hopefully this illustrates a point about the impact of losses.