I'm not sure if it's true that your investment percentage should be at its highest while young. Maybe as a percentage of your total assets? But then it's just a consequence of when you're young you have lower assets. Whereas if you're instead talking about a percentage of your income, say, then perhaps your risky investment should be highest when you're older, because by then you've developed a nest egg that will basically secure your retirement so long as you leave it alone (e.g. with "boring" index funds) you can devote all of your income to whatever risky endeavors without having to worry about the high probability downside of losing it all.
There's some basic math around compound interest that comes into play that young people should consider. While growing up my state required a "financial literacy" course for everyone, I assume that's expanded across the country so most people should be able to do the math if they're so inclined, but I also think charts like these are useful and good enough to get the point across: http://www.businessinsider.com/amazing-power-of-compound-int... Generally speaking, start-time for getting the investment nest egg rolling dominates.
Also even if your appetite for risk is large now, you have to really ask what you want out of any risky endeavor, when you want it realized, and what you'll be satisfied with, since if you'll be satisfied with X there's little reason to pursue some high risk activity that if it works out returns Y >> X but most likely (being high risk) you won't even break even. Consider a risky endeavor that's less risky in that if it works out will give you X, but with the nature of risk the probabilities of not working out are lowered. Boring index funds are a type of this lower risk investment that can satisfy "effectively able to retire" in your 30s, but they're not going to satisfy rich startup gains leading to double-digit millionaire+ status. It's at least a path if you want that certain state of "retirement nest egg" when you're in your 30s, and by extension works if you just want it for your 60s too. On the other hand, maybe you're someone indifferent to when you want unicorn-success riches to be realized (great if tomorrow, fine if 20 years from now after you finally catch a break and haven't died first).
There's some basic math around compound interest that comes into play that young people should consider. While growing up my state required a "financial literacy" course for everyone, I assume that's expanded across the country so most people should be able to do the math if they're so inclined, but I also think charts like these are useful and good enough to get the point across: http://www.businessinsider.com/amazing-power-of-compound-int... Generally speaking, start-time for getting the investment nest egg rolling dominates.
Also even if your appetite for risk is large now, you have to really ask what you want out of any risky endeavor, when you want it realized, and what you'll be satisfied with, since if you'll be satisfied with X there's little reason to pursue some high risk activity that if it works out returns Y >> X but most likely (being high risk) you won't even break even. Consider a risky endeavor that's less risky in that if it works out will give you X, but with the nature of risk the probabilities of not working out are lowered. Boring index funds are a type of this lower risk investment that can satisfy "effectively able to retire" in your 30s, but they're not going to satisfy rich startup gains leading to double-digit millionaire+ status. It's at least a path if you want that certain state of "retirement nest egg" when you're in your 30s, and by extension works if you just want it for your 60s too. On the other hand, maybe you're someone indifferent to when you want unicorn-success riches to be realized (great if tomorrow, fine if 20 years from now after you finally catch a break and haven't died first).