How to Match Fixed-Income Risk to an Investment Horizon

Rohit's down payment is in the wrong place

Rohit and his wife are saving for a home and expect to buy in about two years. Somebody sensible pointed out that leaving the money in a savings account was costing them, and suggested a debt fund instead — reasonable advice, correctly given, and he acted on it.

The fund he chose holds long-dated bonds. It has done well, which is why it appeared near the top of the list he was shown. It will also move several per cent on a change in interest rates, in either direction, and one of those directions arriving in month twenty-two would take a bite out of a down payment that has a date attached to it.

Nothing is wrong with the fund. It is simply doing a job it was never suited for, and that mismatch — rather than any bad product — is where most fixed-income losses actually come from.

The rule the whole thing rests on

Fixed income carries two main risks, and matching solves one of them almost entirely.

Interest-rate risk moves prices and it reverses. A bond that falls when rates rise recovers as it approaches maturity, provided the issuer pays. So if you can wait, a rate-driven fall costs you nothing at all. If you cannot wait, it becomes a realised loss — which is precisely Rohit's exposure.

Credit risk does not reverse. Time does not repair a default, and a longer horizon does not make a weak borrower any safer.

Which gives the rule: horizon determines how much interest-rate risk you can take, and never determines how much credit risk you should. People frequently extend both together, which is half right and half dangerous.

What horizon actually means

Not when you retire, but when this particular money gets spent.

A single portfolio usually contains several horizons at once — an emergency fund that might be needed tomorrow, a fee due next year, Rohit's deposit in two years, retirement money in twenty. Treating them as one pool with one answer produces a compromise that is wrong for every one of them.

Two refinements matter. A horizon can arrive early, through an emergency or a job loss, which is why the emergency fund exists and why other money should not be doing its job. And a horizon can be a series rather than a date: retirement drawdown is spent across decades, so it is not all short-term money on the day you stop working.

Matching by duration

Duration estimates how much a bond or fund moves for a change in rates — roughly its value in per cent for each percentage point — and it is the dial to set by horizon.

Money needed within a year wants duration close to zero: savings accounts, sweeps, short deposits, overnight or liquid funds. You are buying certainty of amount and of access, and the low yield is the price of the property you actually needed. Money at one to three years suits short-duration options of high credit quality, where a modest amount of movement is tolerable because there is some room to wait. Rohit belongs here, not where he currently is.

From three to seven years, medium duration becomes reasonable — a rate rise is a mark-down you can sit through, and you are paid more for the commitment. Beyond that, longer duration is defensible, and a useful rule of thumb applies: if your horizon comfortably exceeds the duration, a rate rise is an inconvenience rather than a loss. You hold, the bonds mature or roll, and the higher rates that hurt initially then work in your favour on reinvestment.

The practical version of all this is to look up the duration before buying, compare it against the number of years until the money is needed, and be uncomfortable whenever duration is the larger of the two.

Why credit does not scale with horizon

The tempting extension is that a long horizon also justifies weaker borrowers. It does not, and the reasoning deserves to be precise.

A default is permanent. Waiting twenty years does not recover money that was never repaid. Time helps with price volatility because the price converges toward a known value at maturity — but only if the issuer pays. Remove that condition and the mechanism making patience valuable simply disappears.

There is a genuine diversification argument for holding some credit exposure in a large portfolio, and professional investors make it. But it is an argument about spreading many small exposures, not about a long horizon making a weak borrower safer. For most individual investors the safe part of the portfolio should stay high quality regardless of horizon, with the appetite for risk expressed in equities where the upside is not capped.

The job the money is doing

Horizon is the main input and purpose is the tiebreak.

Money whose job is safety — an emergency fund, a known obligation on a known date — takes almost no risk of either kind, because certainty of amount is the product being bought. Money whose job is ballast, sitting in a long-term portfolio to hold up when equities fall, should be high credit quality and can carry duration; this is the case where quality matters most, since weaker credit tends to fall alongside equities in a crisis, which is exactly when you needed it not to. And money whose job is return is generally better served by equity, for the reasons above.

Practical arrangements

Separate the pots visibly, in different accounts or funds for different horizons, because mixing them is what leads to selling the wrong thing under pressure.

Ladder where there is a schedule. For a series of known obligations — fees each year, a planned sequence of purchases — deposits or bonds maturing when each is needed remove both risks at once. Let a long-horizon holding roll rather than reacting to a rate move, since the mark-down is the mechanism by which future returns improve.

And recheck as the horizon shortens, which is the most commonly missed maintenance task in a portfolio. Money for a goal four years away becomes money for a goal one year away, and the allocation that was right at the start is wrong near the end. Rohit's fund would have been a perfectly reasonable holding if the purchase were fifteen years off; what makes it wrong is a date that keeps getting closer while the allocation stays still.

What to take away

Match duration to horizon: near zero for money needed within a year, longer as the horizon extends, and be uncomfortable whenever the duration exceeds the number of years you can wait. A rate-driven fall is only a loss if you are forced to sell into it.

Do not extend credit risk with horizon, because time repairs price volatility and does nothing whatever for a default. Keep the safe part of the portfolio high quality whatever the horizon, separate money by when it is needed, and revisit as goals get closer — since the mismatch, rather than the product, is what usually causes the loss.