What Are Real Interest Rates and How Are They Measured?

Nominal rate minus expected inflation

Every bond has a "nominal" yield — the interest rate printed on the label. A regular 10-year US Treasury bond was yielding 5.01% as of September 18, 2026. But that number doesn't tell you what you'll actually keep. If prices in the economy rise by, say, 2% a year while you hold that bond, part of your return just replaces the purchasing power inflation destroyed. The real rate is what's left over: nominal yield minus expected inflation.

The problem is that "expected inflation" isn't printed anywhere. The market has to infer it, and that's where TIPS come in.

What TIPS actually are

TIPS are Treasury bonds whose principal is adjusted for inflation as measured by the Consumer Price Index. If inflation runs at 3% one year, the bond's face value goes up by roughly 3%, and the coupon is paid on that adjusted amount. Because the inflation adjustment is built into the bond itself, the yield TIPS trade at is already a real yield — it's the return above inflation that investors are willing to accept, set directly by market prices every trading day.

That gives us a second useful number for free. Subtract the TIPS real yield from the nominal Treasury yield of the same maturity, and what's left is the market's implied inflation forecast — called the "breakeven rate." As of the most recent reading, the 10-year breakeven sat at 2.34%, and it has been trending higher over the past three months. Put differently: nominal yield (5.01%) minus breakeven inflation (2.34%) lands close to the TIPS real yield itself (2.68%) — the three numbers are mechanically linked, not three independent opinions.

Read this table left to right rather than top to bottom: the nominal yield is what you see quoted; subtract the breakeven (the market's inflation guess) and you land near the real yield. The 5-year real rate has risen faster than the 10-year one over the past year (+132 bps versus +95 bps), which tells you the move has been sharper at the short end of the real-rate curve — often a sign the shift is being driven by Fed policy expectations rather than a slow-moving structural change in growth prospects.

Why gold cares about the real rate specifically

Gold pays no coupon, no dividend, no interest. Holding it means giving up whatever a safe bond would have paid you instead. That forgone amount isn't the nominal yield — inflation would have eaten into the bond's return too, so it isn't a fair comparison — it's the real yield, because that's the actual after-inflation return an investor sacrifices by holding metal instead of a TIPS bond. This is why market commentary treats the 10-year real rate as gold's opportunity-cost benchmark: when real yields rise, the "cost" of holding a non-yielding asset rises with them; when real yields fall, that cost shrinks.

Right now, that opportunity cost is unusually high by recent standards. The 10-year real rate's 2.68% level sits at the 99.2nd percentile of its own past year and the 99.8th percentile of the past five years — meaning over the last five years, real rates have rarely, if ever, been this elevated. Tracing the last eighteen months of TIPS data shows the climb clearly: the real yield was around 1.83% in April 2025, drifted between 1.7% and 2.2% through most of 2025, and has pushed steadily higher since spring 2026, reaching 2.60% by September 14, 2026.

Over the same period, gold has fallen a meaningful amount from its highs: spot gold closed at $4,316.52 on September 22, 2026, down 20.1% from its one-year peak of $5,405.00, and is trading below both its 50-day and 200-day moving averages in what the technical data classifies as a confirmed downtrend. That sequence — real rates grinding higher, gold pulling back from a peak — is consistent with the opportunity-cost story. It is not proof of it.

What the correlation numbers actually show — and where they break down

This is the part that's easy to overstate. Measured on daily price changes, gold's correlation with the 10-year real rate is weak: -0.11 over the past 252 trading days, -0.19 over 63 days, and -0.25 over 21 days (a correlation of -1 would mean they move in perfect lockstep in opposite directions; 0 means no relationship at all). On a day-to-day basis, gold and real rates often appear almost unrelated.

That's not the full picture, though. When you look at how the two series move over longer stretches — comparing the change in gold's price over rolling 60-day windows to the change in the real rate over the same windows — the inverse relationship becomes much clearer, with a correlation of -0.52. The underlying data explicitly flags why: real rates move in small increments day to day, while gold's price can swing on unrelated news (currency moves, geopolitical headlines, central bank buying), so daily correlation is simply too noisy an instrument to detect a relationship that shows up over months. A near-zero daily correlation does not disprove the real-rate channel — it just isn't built to measure it.

The takeaway, and what it doesn't tell you

The real interest rate is the nominal yield on a bond minus the inflation the market expects it to lose to, and TIPS let us read that number directly off market prices every day rather than guessing at it. The 10-year real rate is the figure gold-watchers track most closely because it approximates the cost of holding an asset that pays no income, and that rate is currently near multi-year highs while gold has pulled back from its own peak.

What this doesn't show is causation, and it doesn't show what happens next. Real rates are one of several forces acting on gold at any given time — the dollar, central bank demand, and risk appetite all move independently and sometimes overwhelm the real-rate channel entirely. Our own historical testing has not found a reliable, tradeable edge from watching real rates in isolation, and nothing here should be read as a forecast for where gold or real yields are headed. If you want to follow the data releases that move these numbers — CPI prints, TIPS auctions, Fed decisions — as they land, the schedule is tracked on the MacroGold calendar.