What it means
The idea is that the portfolio keeps doing the same job while one holding is replaced with a better version of it. Because the sale and purchase happen together, the investor is rarely out of the market and the change in exposure is deliberate rather than accidental.
The most common motive is a yield pickup swap. If a bond of similar credit quality and maturity is available at a higher yield, switching captures the difference for the remaining life of the holding.
A tax swap is the second big reason. Selling a bond that has fallen in value crystallises a capital loss that can be set against gains elsewhere, while buying a similar but not identical bond keeps the portfolio's shape intact.
Two other varieties turn up regularly. A maturity swap shortens or lengthens the portfolio's average life ahead of an expected move in rates, and a quality swap trades yield for safety by moving up the credit ladder, or the reverse when spreads look generous.
Costs decide whether a swap is worth doing. Dealer spreads, settlement charges and the loss of any accrued interest advantage all eat into the benefit, so a pickup of a few basis points rarely survives contact with the trading desk.
Tax rules add a trap. Many jurisdictions disallow a loss if a substantially identical security is repurchased within a set window, so a tax swap has to move into a genuinely different bond rather than buy back the same one.
In practice
Real-world examples.
Example
An investment manager holds a bond yielding 4.1% and spots an almost identical issue from a comparable borrower at 4.6%. She swaps the position, capturing half a percentage point of extra income without changing the portfolio's risk profile in any meaningful way.
Example
A private investor sitting on a large gain from a property sale wants to reduce the tax bill. He sells bonds standing at a loss to offset the gain and immediately reinvests in a different issuer of similar quality, keeping his income roughly unchanged.
Example
A pension fund expects rates to rise and swaps out of twenty-year bonds into five-year bonds. The move cuts the fund's sensitivity to rate moves, at the cost of giving up some current yield.
Formula
Calculation
Annual yield pickup = proceeds x (new yield - old yield)
Total benefit = annual yield pickup x years remaining - transaction costs
An investor sells a bond and receives $500,000 in proceeds. The bond being sold yields 3.90%, producing $500,000 x 3.90% = $19,500 a year, and the replacement bond of similar quality and maturity yields 4.35%, producing $500,000 x 4.35% = $21,750 a year.
The annual pickup is $21,750 - $19,500 = $2,250, which is the same as $500,000 x 0.45% = $2,250. With six years left to maturity on both bonds, the gross benefit is $2,250 x 6 = $13,500.
Transaction costs on the two trades come to about $1,500, so the net benefit is $13,500 - $1,500 = $12,000. That comfortably justifies the swap, whereas a pickup of only 0.05% would have produced $250 a year and been wiped out by the same costs.Case study
Seen in the real world.
The following is an illustrative and entirely fictional example. Pelham Ridge Foundation, an invented charitable endowment, held $1,000,000 of bonds bought at par with a 3.2% coupon, producing $1,000,000 x 3.2% = $32,000 a year. After a sharp rise in market rates the bonds were quoted at 92, so their market value had fallen to $1,000,000 x 92 / 100 = $920,000.
The finance committee's first reaction was to hold on and wait for recovery. Its adviser pointed out that the loss had already happened, and that selling would crystallise $1,000,000 - $920,000 = $80,000 of capital loss usable against gains in the equity portfolio.
The foundation sold and reinvested the $920,000 in a different issuer of similar credit quality yielding 5.1%, producing $920,000 x 5.1% = $46,920 a year. Annual income rose by $46,920 - $32,000 = $14,920 and the fictional endowment also banked the tax benefit, all without changing the overall shape of its fixed income holdings.
Watch out
Common mistakes.
- Confusing a bond swap with an interest rate swap, which is a derivative contract exchanging fixed and floating payments rather than a purchase and sale of bonds.
- Chasing a higher yield without asking why it is higher, and unknowingly swapping into weaker credit quality or a longer maturity.
- Ignoring dealer spreads and settlement costs, which can consume the entire benefit of a small yield pickup.
Questions
People also ask.
Does a bond swap crystallise a taxable event?
Yes. The sale leg realises whatever gain or loss has built up, which is the entire point of a tax swap and an unwelcome side effect of every other kind.
How big does a yield pickup need to be?
Enough to cover trading costs several times over, which in practice usually means at least a quarter of a percentage point on a holding with years left to run.
Can I swap back into the same bond later?
Usually yes, but not immediately if you claimed a tax loss, because repurchase rules in many jurisdictions disallow the loss if you buy back a substantially identical security too soon.
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