The question I keep asking, and getting no answer to, is: "What Investments?" What investments are reasonable enough that they can stack up as a risk you should take versus paying off the (admittedly amazingly low interest rate) mortgage?
We keep talking about "investment" like it's this giant cash machine where you'll never lose a dime. Of course a reasonable answer is "diversification", but you can't diversify much if you don't already have a boatload of cash to invest.
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But if I'm going to be "smarter guy" and come out richer, how do I do it? Is it as simple as going into Vanguard indexed funds or Betterment and let'er ride?
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Hi mefla
This conversation seems to have gotten a bit heated, so lately I've kept my distance (plus I've had a few RL emergencies to deal with).
A few thoughts: The 4% WR was based on the trinity study which looked at all monthly historical periods of the
SP500 plus US treasury bonds. To paraphrase, it concluded that you can withdraw 4%/year regardless of market conditions and have a very low (but not 0%) probability of running out of money over any 30 year period.
The key word above is SP500. In your earlier statement you asked about "diversification" - that's exactly what an SP500 index fund gives you. You do not need "a boatload of cash to invest" to have diversification now-a-days... you only need $1,000 to put into Vanguards SP500, Total Market, or even blended index funds (which includes the SP500 + bonds). Investing in individual stocks will inherently be more risky than investing in 500 of the largest companies, because as you've rightly stated, if one tanks your portfolio can take years (or decades) to recover.
EDIT:
As Vikyb rightly pointed out, there are even cheaper ways of achieving broad diversification into US and international equities plus bond funds. You can achieve a level of diversity today with a few hundred $ that we couldn't dream of just 20 years ago.
Finally, regarding 'risk' - there's two sides to every risk equation. The first side is what you stand to loose if you make an investment, and this is the side that people tend to focus on, mostly because it's easy to understand and fairly easy to calculate. If I have $100k, and the market drops 20%, I "loose" $20k (but only on paper, unless I sell). The other side of the 'risk' coin is what you loose by not making the investment. This is largely ignored, harder to calculate and I think a source of the confusion here. For example, let's say you have $100k again. If you keep it in a safety-deposit box for 20 years (or in a 0% yield insured Money Market Account) you can be assured that you will have $100k in 20 years. The risk of loss at first appears to be 0. "That's as safe as you can get!" some people will say.
But we realize that isn't true. In fact you lose out to inflation every year, so that $100k will be worth about $60.1k in 20 years (2.5% inflation). But the real 'risk' is losing out on what you could have earned had you placed it in an SP500 fund. This is admittedly hard to calculate/predict, but we can use history as a guide. For 20 year periods, the SP500 has given an annual return of 0.7% to 13% after inflation. That gives you a spread of $115k to $3.9M. That's a huge range, but in all cases it's better than cash or a savings account (at current yields). Since your mortgage is fixed (inflation hedge), the SP500 also beats out paying down a mortgage early. FYI the median return over 20 year periods would be $466k.
This is what boarder42 and others mean when they say that it's more 'risky' to pay off a mortgage at 3% - they are taking into account the loss you would incur if you had invested.
All of this of course assumes that the future will operate more-or-less the same as the recent past, which is another lively argument that comes up on these boards.