What it holds
Government securities, almost exclusively. The borrower is the sovereign, which is as close to default-free as rupee lending gets.
Which resolves one of the two risks in every debt fund and leaves the other entirely untouched. There is no credit analysis to do here, no rating breakdown worth studying, and no possibility of a write-down.
What remains is duration — and gilt funds usually carry a lot of it, because government bonds are issued across long maturities and gilt funds tend to hold the longer end.
Why the safest borrower produces the bumpiest fund
Here is the sentence that surprises people: a gilt fund can be the most volatile debt category on the list.
Bond prices move inversely to yields, and how far they move is given by modified duration. A long-dated gilt fund with a modified duration of eight will lose roughly 8% of its value on a one-percentage-point rise in yields — a larger fall than many conservative equity-hybrid investors would tolerate.
“Government backed” is doing precise work in the phrase and much less than it suggests. It guarantees you will be repaid. It says nothing about what the holding is worth in the meantime, and a fund marks its holdings to market every day.
Which is why gilt funds are frequently mis-sold. Presented as the safest debt option because the borrower is safest, they are handed to investors who then experience a drawdown they were told could not happen.
Constant maturity is a different product
An ordinary gilt fund's manager varies duration according to a view on rates. A constant maturity gilt fund is mandated to hold a fixed portfolio duration — it buys longer bonds as its holdings age, so the duration never falls.
One precision that is worth more than it looks. The 10-year constant maturity category is defined by duration, not by average maturity — the portfolio's Macaulay duration must be held at ten years. These are different quantities, and they are routinely swapped in commentary. Average maturity is when the bonds come due; duration is how far the price moves when yields shift. Since the entire reason to hold this category is a known, unchanging rate sensitivity, the number that is actually pinned is the one that determines your losses — which is the right one to pin, and the one to look up.
Two consequences.
There is no manager view. You get pure, undiluted exposure to the rate cycle at a known duration. That is either exactly what you wanted or the opposite of it, depending on whether you were seeking a rate position or expecting someone to manage one.
It never matures down. An ordinary bond held to maturity returns its face value regardless of what happened in between — but a constant maturity fund never gets there, because it keeps rolling into longer paper. There is no point at which duration risk resolves itself, which is the opposite of holding a single bond to maturity.
Who it is actually for
Three legitimate uses, and one common wrong one.
Expressing a view that rates will fall. A long gilt fund is the cleanest instrument available for it — no credit noise, just duration. Whether you should hold a view on rates is a separate question, and professional forecasters get direction wrong regularly.
Matching a long, known liability. Where money is needed at a distant fixed date, a duration roughly matching that horizon means rate moves largely wash out, as set out in matching duration to horizon.
Removing credit risk deliberately, where the priority is that nothing can default even at the cost of price volatility.
The wrong use is as a safe parking place for short-term money. For that purpose the duration is a liability rather than a feature, and a liquid or overnight fund is the right answer. Short money in a long gilt fund is the mis-sale this category produces most often.
What to check
- Modified duration. The single most informative number — multiply it by a plausible rate move to see the swing you are accepting.
- Whether it is constant maturity or actively managed. Very different products under similar names.
- Maximum drawdown in past rate cycles. This is history rather than theory and it is the honest test of whether you can hold the fund.
- Expense ratio. There is no security selection to pay for here, so cost matters more than in categories where a manager is doing something. Two gilt funds of similar duration differ mainly on cost.
- Whether it holds state development loans alongside central government paper, which carry slightly different characteristics.
Point four deserves weight. In a category with no credit decisions and a mechanical strategy, a high expense ratio is difficult to justify, and it comes directly out of a modest yield.
Seeing the volatility rather than describing it
The claim that a gilt fund can fall meaningfully is testable against history rather than argued.
FNOTrader's Mutual Funds app carries the full AMFI NAV history — around 34 million NAV rows — so a gilt fund's worst drawdown through past rate cycles, and how long it took to recover, are directly inspectable. Compare that drawdown against a short duration fund over the same period — the gap is what the duration bought, and whether it was worth it depends entirely on your horizon.
FNOTrader is not a SEBI-registered investment adviser and does not recommend schemes.
Common questions
What is a gilt fund?
A debt fund that lends almost exclusively to the government by holding government securities. That removes credit risk almost entirely, since the borrower is the sovereign, and leaves interest-rate risk untouched.
Are gilt funds safe?
They are safe from default and frequently the most volatile debt category. A long-dated gilt fund with a modified duration of eight can lose roughly 8% on a one-percentage-point rise in yields — 'government backed' guarantees repayment, not what the holding is worth in the meantime.
Why are gilt funds so volatile?
Because government bonds are issued across long maturities and gilt funds tend to hold the longer end, so their modified duration is high. Price moves inversely to yields in proportion to duration, and the fund marks holdings to market daily.
What is a constant maturity gilt fund?
One mandated to hold a fixed portfolio duration, buying longer bonds as holdings age so duration never falls. There is no manager view on rates, and crucially it never matures down — so duration risk never resolves itself the way holding a single bond to maturity does.
Who should consider a gilt fund?
Someone expressing a considered view that rates will fall, someone matching a long known liability where duration roughly matches the horizon, or someone deliberately removing credit risk at the cost of price volatility.
Are gilt funds good for short-term parking?
No, and this is the most common mis-sale in the category. For short-term money the duration is a liability rather than a feature — a liquid or overnight fund is the appropriate instrument.
What should I compare between two gilt funds?
Modified duration first, whether the fund is constant maturity or actively managed, historical maximum drawdown through rate cycles, and expense ratio — which matters more here because there is no security selection to pay for.
Continue reading
More in Mutual Funds · App: Mutual Funds · Definitions: glossary · Free tools: calculators · All: every article