To illustrate Hank's point, suppose you bought a
10 year Treasury on Jan 5,
1973, and held it though Aug 23,
1974. So you'd have purchased a bond maturing on Jan 5,
1983. Assume that coupon matched market yield (newly minted bond).
The yield on that semi-annual bond was 6.42%. On Aug 23,
1974, the yield on
10 year Treasuries was 8.
15% (probably slightly lower for this bond as it was now an 8.4 year bond).
http://www.macrotrends.net/2016/10-year-treasury-bond-rate-yield-chartUsing 8.
15% YTM, 6.42% coupon, and a bond calculator
here, we get an ending price of $88.8
1. That is, the bond dropped in price by about
11%.
The yield on that bond was 6.42%/year. So over the period of
1.63 years the interest was about
10.5%. That makes the net return on the bond about -0.5% (more or less a wash), while the S&P 500 dropped from
119.87 to 7
1.55 (-40.3%).
http://www.davemanuel.com/where-did-the-djia-nasdaq-sp500-trade-on.phpIf we were to go through another period of stagflation now, with
10 year T's yielding around 2.5%, and a similar
1.73% rise in rates, the calculator shows the price declining by
13.3% (
lower coupon = longer duration). Then there's the
lower interest this time around. 2.5% for
1.63 years returns just 4.
1%.
So this time, the same rise in interest rates (seven
1/4 pt hikes at a roughly quarterly pace) would produce a bond loss of about 9%, vs. the previous experience of a wash (including interest). Bonds as "ballast" have the potential to hasten a ship going down.
One can certainly quibble with my calculations - I've made approximations that somewhat exaggerate the losses. I've not reinvested coupons (i.e. I just computed simple interest), and I've not accounted for the shortening maturity of the bond. Making these adjustments won't significantly affect the total bond return. You'll still lose a lot.
The US employment market is much tighter than it has been the past several years. Throw a couple of trillion dollars at it in infrastructure spending and tax cuts (read: more borrowing), and you may see interest rates go up both because of increasing inflation (spurring Fed action) and the increased borrowing.
That's not a prediction of what the government or economy will do. It's simply a case study of how bonds can harm a portfolio in a 70s-like stagflation, where the key difference is, as Hank pointed out, lower starting bond yields.
http://www.businessinsider.com/wall-street-worried-trump-1970s-stagflation-2016-11