William Bernstein on Holding Both Treasury Bonds and TIPS (or Savings I Bonds)

William Bernstein has a new article titled Riskless at Age 104 in which he outlines why he just bought some 30-year Treasury Inflation-Protected Securities (TIPS) that won’t mature until he is 104 years old. Despite that distracting headline, the article is more about the reasons why you might want to hold both traditional US Treasury bonds that pay a stated rate and TIPS that pay a stated rate above inflation.

Here’s a quote that is nearly the answer to a riddle: What is risky in the short run but riskless in the long run? What is the opposite?

A TIPS is risky in the short term and riskless in the long run, which is precisely the opposite of, and complementary to, a T-bill, which is riskless in the short term but, because of reinvestment rate volatility, risky in the long run.

In the end, Dr. Bernstein recommends holding both:

To summarize, TIPS and T-bills are complementary assets. The former appeals to our System 2’s inner Spock, who first and foremost wants to secure our future consumption, while the latter assuages our System 1’s inner Daffy Duck, who wants us to bail at the worst possible time and violate Charlie Munger’s first rule of compounding, which is to never interrupt it.

The prudent retiree holds a goodly pile of both.

I also split the bond portion of my portfolio between safe traditional bonds (and cash and CDs) and safe inflation-protected bonds. My take:

• Cash, which can be held in the form of short-term Treasury Bills or cash deposits in an FDIC-insured bank account, satisfies our System 1 “reptile brain”. It’s simple, reliable, and easy to understand. It may not keep up with inflation perfectly, but it also moves around a lot less.
• TIPS and I Savings Bonds, which allow you to remove the variable of unexpectedly high inflation over long period of time (up to 30 years out), satisfies our System 2 “rational brain”. As a long-time holder, I can attest that it fluctuates in unpredictable ways and is not that much fun to hold. It’s actually like stocks in that price seem to drop in times of crisis. You have to really understand the inner workings, but if you do then it becomes a form of long-term insurance against unexpectedly high inflation.

This is also why I’m still buying Savings I Bonds every year even though the headline rates are not as crazy anymore. I don’t buy them as a substitute for short-term cash, but as a form of long-term insurance policy. When inflation spiked up to 8%+, it wasn’t just $10k of I Savings Bonds that I bought in 2022 that went up 8%+. My entire stash of I Savings Bonds slowly accumulated over a decade or more went up 8%+. I will admit, it felt nice that something went up in 2022. Savings I Bonds also never go down in value (unlike TIPS), so in a way they are the least stressful way to hold inflation-protected bonds.