What Is Reinvestment Risk?

Michael Whitman · Trading since 2017, full-time since 2020 · YouTube creator, 137K subscribers · Published 2026-09-14 · Updated 2026-10-27

Interest rate risk is what happens to the price of what you hold. Reinvestment risk is what happens to the money coming back, and the two move in opposite directions.

How it works

Investments return cash along the way — coupons, dividends, maturing principal — and that cash has to go somewhere.

If rates have fallen, it is redeployed at less. The income stream you were counting on shrinks without anything going wrong with the original holding.

And your existing holdings rose in price at the same time. The two exposures offset, which is why somebody holding to maturity is affected by one and somebody selling is affected by the other.

Rolling 26-week bills meant a rate of 5.318% in mid-2006 and only 0.254% two and a half years later, which is the rollover risk described in Treasury bills.

Coupon over price, the current yield, leaves out the pull to par; on 23 Oct 2026 it was more than a full point off yield to maturity on 121 of 299 Treasuries.

Where it is concentrated

Callable bonds are the worst case. The issuer redeems early when rates have fallen, which is precisely when you cannot replace the income.

Mortgage securities have the same property. Homeowners refinance when rates fall, returning principal early, and the effect is the same as a call without anybody deciding it.

High-coupon bonds carry more of it. More of the return arrives as cash along the way, so more of it needs reinvesting at whatever rate then exists.

SPY and IEF daily returns moved against each other from 2003 through 2021 (-0.39) but together since 2022 (+0.11), according to bond market.

A worked example

A ten-year bond with a 6% coupon, bought at par. Its quoted yield to maturity is 6%.

That figure assumes every coupon is reinvested at 6% for the remaining term. Reinvest them at 2% instead and the realized return over the decade is materially below 6%.

The bond performed exactly as contracted. Every coupon arrived, the principal was repaid in full, and the realized return was still lower than the number on the confirmation.

Which is why zero-coupon bonds are the exception. An accrual bond pays nothing along the way, so there is nothing to reinvest and the quoted yield is the return you actually get.

The two risks offset, and that is useful

Rates rise: prices fall, reinvestment improves. Rates fall: prices rise, reinvestment worsens. The two exposures point in opposite directions.

At one particular horizon they cancel exactly. That horizon is the bond’s duration, which is the deeper reason bond duration is the central number in fixed income rather than merely a sensitivity measure.

Immunization is built on this. Matching a portfolio’s duration to the date a liability falls due makes the outcome approximately independent of what rates do in between.

Which is the practical answer to both risks at once. It is how pension schemes and insurers manage known future obligations, and it requires no forecast of rates at all.

The original data

Run the worked example to maturity. Reinvested at 6%, the ten coupons of 6 grow to 79.08 by the final year; reinvested at 2% they reach only 65.70. Add back the 100 of principal and the realized return is about 5.2% a year rather than the quoted 6%, from the reinvestment rate alone.

That gap is compounding at work. The rate at which returned cash is redeployed, applied repeatedly over decades, moves the final outcome by more than most people expect from a difference that looks small in any single year.

And each reinvestment pays a spread or a dealer markup. Frequent small reinvestments pay that repeatedly, which is a second, quieter drag on the same cash flows.

Where it shows up outside bonds

Cash savings. A fixed-rate deposit maturing into a lower-rate environment is exactly this risk, experienced by people who would never use the term.

Dividend income. Reinvested dividends buy whatever the market then offers, and a rising market means each reinvestment buys less future income.

And structured products. Anything that returns capital early on a trigger hands the money back at a moment chosen by the issuer, which is rarely the moment that suits the holder.

The common thread is who chooses the timing. Reinvestment risk is most damaging where the counterparty decides when the cash comes back, because they will choose the moment that benefits them.

How it is managed in practice

Laddering. Holding bonds maturing in successive years means only a portion is reinvested at any one rate, which averages the reinvestment rate over the cycle rather than betting on one moment.

Duration matching. Setting portfolio duration equal to the horizon makes price and reinvestment effects offset, which is the formal version of the same instinct.

Avoiding callable structures removes the case where the counterparty chooses the worst moment for you, at the cost of a lower yield.

And accepting zero-coupon instruments where a date is known. Nothing is returned along the way, so nothing needs reinvesting, and the quoted yield is the realized one.

How this connects

Short-term cash carries the most of it. Treasury bills, a certificate of deposit and a money market fund all return or reset principal quickly, so their income follows rates down almost immediately.

A puttable bond hands the timing to the holder. Where a callable structure lets the issuer choose, the put lets the lender choose, which limits price risk when rates rise but does nothing for reinvestment when they fall.

Convexity is the price side of the same problem. Bonds whose cash can be returned early show negative convexity, gaining less as rates fall, which mirrors the reinvestment loss on the income side.

Bond fund holders meet it continuously. A fund keeps replacing maturing holdings, so its distributions drift toward current rates, and the yield curve gives a rough idea of where they are heading.

Locking a rate trades one risk for others. An annuity or a long fixed-rate bond holds income steady for years, exchanging reinvestment risk for inflation eroding the payments and for credit risk on whoever promised them.

And it matters most once income is being spent. Income investing for passive income inside retirement accounts depends on redeployment rates far more than a growing portfolio does, because there is no new money arriving to average in.

When it fails

The characteristic failure is planning income from a yield to maturity figure. A retiree builds a budget from the quoted yields on a bond portfolio, and those figures embed an assumption that every coupon is reinvested at the same rate for the full term. Rates fall, the coupons are redeployed at a fraction of the original, and the realized income falls short of the plan by a margin that grows each year. Nothing defaulted and no calculation was wrong — the number quoted was a projection conditional on an assumption that the confirmation did not mention.

A second failure is buying callable bonds for their higher yield, where the extra is compensation for exactly this.

A third is holding high-coupon bonds for income in a falling rate environment, which maximizes the exposure.

A fourth is ignoring it because prices rose. The gain on the holding and the loss on future income are the same event.

The question: Rates fell and the bond was called. Now what?

And a fifth is treating yield to maturity as a promise. It is a projection with a reinvestment assumption inside it.

Related

Bond duration covers the horizon at which this and price risk cancel. Callable bond covers the structure that concentrates it. And yield to maturity covers the measure that assumes it away.

This page is educational, not financial advice. Test every idea on your own charts before risking money.