Carry-Roll-Down

What Is Carry-Roll-Down?

Carry-Roll-Down is the total return a fixed income position earns over a holding period assuming the yield curve remains unchanged — it is the sum of carry (net coupon income minus financing cost) and roll-down (price appreciation as the bond shortens in maturity and moves to a lower-yield point on an upward-sloping curve). Understanding the distinction matters: carry is the income component, while roll-down is a capital appreciation component driven purely by the shape of the curve. A 10-year Treasury that yields 4.50% financed at SOFR of 5.30% has negative carry of approximately -80 basis points annualized, but if the 9-year point yields 4.30%, the bond rolls down 20 basis points of yield over one year — producing roughly 1.4 points of price appreciation on a duration-7 instrument, partially offsetting negative carry. The net carry-roll-down is the arithmetic combination of both effects, often expressed in basis points per month or as an annualized percentage.

Why It Matters for Traders

Carry-roll-down is the silent P&L engine of fixed income portfolios. When traders talk about a trade 'paying you to wait,' they are describing a high carry-roll-down position. In a steepener trade or butterfly trade, carry-roll-down is often the primary source of expected return — the trade profits even if rates do not move. Conversely, many duration-extension trades have deeply negative carry-roll-down, meaning the trader must be correct on the directional rate move within a finite horizon or suffer steady erosion. For cross-asset carry strategies, fixed income carry-roll-down feeds directly into total portfolio carry calculations alongside FX carry and credit spread carry.

How to Read and Interpret It

Practitioners calculate carry-roll-down in three steps:

1. Carry: Yield of the bond minus the short-term financing rate (repo or SOFR). This is the net income per unit of duration per year.
2. Roll-down: The yield difference between the bond's current maturity and its maturity one year hence, multiplied by the modified duration at the future date. A steeper curve produces more roll-down.
3. Total: Carry + Roll-down, expressed in basis points per annum or as a dollar P&L per $1mm DV01.

A carry-roll-down above +50 bps/year in the current rates environment is considered compelling for relative-value fixed income strategies. A negative carry-roll-down requires a directional rate view to justify the position — the breakeven yield move needed to offset negative carry-roll-down is a critical risk management input.

Historical Context

The 2004–2006 Fed tightening cycle created a notorious carry-roll-down trap. The Fed raised the Fed Funds Rate from 1.00% in June 2004 to 5.25% by June 2006, yet the 10-year Treasury yield barely moved — the 'Greenspan conundrum.' Traders positioned in 2-year Treasuries expecting to earn positive carry-roll-down as the curve normalized found the front-end rising rapidly while the long end stayed anchored, producing an inverted yield curve by 2006. Carry-roll-down on 2-year notes turned sharply negative as their yield rose above the 10-year, and roll-down evaporated entirely once the curve flattened. Traders who had assumed static carry-roll-down as their base case P&L suffered significant mark-to-market losses even without taking outright duration positions.

Limitations and Caveats

The fundamental assumption underlying carry-roll-down is curve stasis — that yields at each maturity remain unchanged over the holding period. In practice, yield curves shift, twist, and butterfly constantly. Carry-roll-down can reverse violently: a bear steepener that lifts long-end yields destroys roll-down value on long positions. Additionally, for non-sovereign bonds, credit spread widening can offset or overwhelm carry-roll-down, meaning the concept must be adjusted to include spread carry separately. Embedded negative convexity in mortgage-backed securities further complicates carry-roll-down calculations since prepayment optionality alters effective duration as rates change.

What to Watch

• Curve steepness at the 2s10s and 5s30s points: steeper curves generate more roll-down, making long positions more attractive on a carry-roll-down basis.
• Repo rates vs. coupon levels: when SOFR or repo rates exceed coupon yields, carry turns negative and the full burden falls on roll-down to justify holding.
• Forward curve shape: carry-roll-down is greatest when the forward curve is elevated above spot rates, implying the market expects significant rate rises that fail to materialize.
• Duration extension flows: institutional demand for long-duration assets often signals that carry-roll-down calculations are supportive of extending maturity.