Which is exactly what Vanguard Retirement funds do, automatically.

I really don't understand why some of you take this "advice" so to heart. As if this is just cut into stone, and you follow it to the letter. This is a good general guideline to follow for someone that is completely clueless about what to do with investing. You've got guys further down the thread proposing you write your own day trading software, because THAT will surely work out in your favor. Do your research. Geez.

The people here seem to be presenting extreme positions. On the one side, you can't beat the market unless you're a hedge fund or big player with special knowledge and equipment, so buy index funds or you're a naughty gambler. On the other side, we degenerate into self-creating automated trading software.

There's absolutely a middle ground here, folks. One can have a portfolio of conservative picks (index funds), self-selected individual picks, cash, bonds, so on and so forth.

This should hopefully be picked up by n-gate to make a mockery of us.

Joking aside, I'm curious what some of you who are actually paid to write front office software by Wall St. think of all of these threads.

Rule of thumb: 100 - your age = % of your portfolio you should have in stocks.

There have been a lot of rules of thumb over the years. 50/50 and 60/40 used to be common advice, no matter the age of the investor. When modern portfolio theory became influential, the "age in bonds" rule of thumb became common. Now some people, e.g. Burton Malkiel and others who are involved with the robo-investing companies, say that young people don't need bonds at all, and that high-dividend blue chip stocks can be a good substitute: https://blog.wealthfront.com/investor-bond-market/

There's no simple answer. There might be a right answer, but so far no consensus view has lasted for long. Most of the arguments I've seen have been heavily dependent on bond yields at the time the arguments were made, and are therefore not universal advice. For example, 50/50 made a lot more sense when treasury bonds were paying more than 7% per year.

I take no position on this particular rule of thumb but to note it is much less aggressive than more broadly held advice on the subject.