Roll-Down Return on Government Bonds

A roll-down return on a government bond is the price gain an investor captures simply by holding a bond as time passes and it “rolls down” an upward-sloping yield curve to a lower yield. If a 5-year Treasury yields 3.50% and a 4-year Treasury yields 3.25%, a buy-and-hold investor purchasing the 5-year bond will see its yield converge toward 3.25% over a year, generating a capital gain beyond coupon income. This is one of the three sources of bond returns—along with coupon and duration changes—and it becomes significant when the yield curve is steep.

The mechanics of rolling down

Imagine the yield curve looks like this on the purchase date:

An investor buys $100,000 of the 5-year Treasury at 3.50% yield. One year passes. The investor has collected one year of coupon payments (roughly $3,500). More importantly, the bond that was a 5-year bond is now a 4-year bond. If the curve has not shifted—if it has maintained the same shape—the bond should now yield 3.25%, the yield the 4-year Treasury carried a year ago.

When a bond’s yield drops from 3.50% to 3.25%, its price rises. A decline in yield of 25 basis points generates a price appreciation. On a bond with a duration around 4 years, a 25 bps yield drop translates to roughly a 1% price gain, or $1,000 on the $100,000 position. Added to the $3,500 coupon, the total return is $4,500 on $100,000 in one year, or 4.5%—higher than the initial 3.50% yield.

That extra 1% comes entirely from the roll-down: the bond earned its coupon (3.50%), plus a price gain (1%) from moving down the curve. Without roll-down, the return would equal the coupon. The price gain is free money if the curve shape holds.

Why roll-down happens

The yield curve is not flat; longer-maturity bonds typically carry higher yields to compensate investors for duration risk and the uncertainty of future rates. As time passes and a bond gets closer to maturity, it sheds duration. A 5-year bond after one year is now a 4-year bond—it has less time risk. The market no longer demands as much extra yield for holding it. Its yield converges downward toward shorter-maturity yields.

This is not an active trading gain—the investor does not sell bonds at opportune moments. It is mechanical. The investor simply buys and holds while the curve does the work. The bond naturally rolls down the curve as calendar days pass, and if the curve shape does not change, yields converge lower, prices rise, and the investor collects a roll-down gain.

Steep curves offer larger roll-down

The bigger the difference in yield between the bond’s maturity and the maturity it will become, the larger the roll-down gain. On a very steep curve—say a 10-year bond yielding 4.00% while a 9-year yields 3.50%—buying the 10-year and holding one year delivers a 50 bps roll-down benefit. On a flat curve where the 10-year and 9-year yield the same, roll-down is zero.

This is why bond investors love steep curves. In the early days of the post-2008 recovery, the Federal Reserve held short rates near zero while longer rates were higher, creating a steep curve. Investors buying 10-year Treasuries collected substantial roll-down returns for years. In 2022–2023, as the Fed cut rates aggressively, the curve steepened again and long-bond investors captured meaningful roll-down.

Conversely, in periods of curve flattening or inversion, roll-down turns negative. If the curve flattens and the 5-year bond you hold approaches the yield of the 4-year, you lose the roll-down windfall.

Roll-down vs. carry vs. duration effects

A bond’s total return over a holding period comes from three sources:

1. Coupon (carry): The interest payments received. A 3.50% bond pays 3.50% per year in coupon.

2. Roll-down (curve shape): The price gain from moving down the yield curve as maturity shortens.

3. Duration changes (market moves): The price change from yield shifts across the entire curve. If the 5-year yield rises from 3.50% to 3.75%, the bond falls in price regardless of roll-down.

A crude decomposition: if the curve holds flat and yields do not move, the return is coupon plus roll-down. If yields rise uniformly across the curve (the duration effect), that can wipe out or reverse roll-down gains. If the curve steepens, longer bonds see negative roll-down relative to what was expected, but if rates fall overall, the duration effect can dominate.

Professional bond managers think in these three buckets. They decide how much curve risk to take (roll-down exposure), how much to hedge (duration), and how much coupon to collect. A manager bullish on an asset class but wanting to avoid outright directional rate bets might buy long bonds in a steep curve to capture roll-down while hedging duration.

Worked example: quantifying roll-down

Suppose today the yield curve is:

• 4-year: 3.20%
• 5-year: 3.50%

Bond A (5-year, 3.50% coupon): An investor buys at par (price = $100).

• Market price today: $100
• Yield today: 3.50%

One year passes. Assume the curve does not shift. Bond A is now a 4-year bond, so it should yield 3.20%.

Price of a 4-year bond with 3.50% coupon and 3.20% yield:

• Coupon payments: $3.50 per year for 4 years, plus principal $100
• Discount rate: 3.20%
• Price ≈ $101.15 (the bond trades above par because its coupon exceeds the new yield)

The investor’s total gain over the year:

• Coupon received: $3.50
• Price appreciation: $101.15 − $100 = $1.15
• Total gain: $4.65
• Total return: 4.65%

Breaking it down:

• Coupon (carry): 3.50%
• Roll-down: 1.15% (the price appreciation from rolling down the curve)

The 1.15% roll-down came from the curve maintaining its shape. If instead the entire curve had shifted up (yields rose 50 bps everywhere), Bond A would have faced a price decline that offset roll-down. If the curve had flattened and the 4-year yield rose to 3.40%, the roll-down benefit would have been smaller.

Curve flattening and roll-down reversal

The flip side: if the yield curve flattens while you hold the bond, roll-down disappears or reverses. Suppose the curve in six months narrows: the 4-year yield rises to 3.40% instead of staying at 3.20%. Now your 5-year bond, halfway through its holding period, sees a smaller roll-down benefit and faces a price decline from the broader market move. The investor loses money relative to buying and immediately selling a 4-year bond.

This risk—that the curve will flatten before roll-down is captured—is real. Many bonds held in a steep curve environment see disappointing returns if the curve normalizes. Conversely, if the curve steepens, roll-down becomes a headwind.

Roll-down in portfolio positioning

Sophisticated investors use curve steepness to guide portfolio positioning. When the curve is steep, overweighting longer-duration bonds or specific maturities positioned for roll-down becomes attractive. When the curve is flat or inverted, roll-down is not a compelling source of return, and investors focus instead on absolute yield or directional bets.

The carry-trade version of roll-down involves borrowing short-term (at low cost) to buy longer bonds in a steep curve. The investor captures the roll-down and carry (coupon minus borrowing cost). This works as long as the curve does not flatten or invert and the borrowing rate does not spike. Many hedge funds and proprietary traders explicitly model roll-down as a profit source.

See also