Conceptual · Article 2.1.1.15

Gilt 10-Year Constant Duration Funds.

The Wall Clock Stuck at 10. Mechanical, Sharp, Patient.

Published as on 17 June 2026

A Gilt Fund with 10-Year Constant Duration is a passive-like debt mutual fund that invests at least 80% in G-Secs and SDLs while mechanically maintaining portfolio Macaulay duration always around 10 years. Unlike Target Maturity Funds (countdown timer reducing duration over time), this is a wall clock stuck at 10. The manager continuously sells 9-year bonds and buys 11-12 year bonds to hold the average. Feb 2026: RBI repo 5.25% after 125 bps cuts during 2025. NAV swings ±10% per 1% rate change. Sharpest rate-cycle tool in mutual funds. Tax under Finance Act 2023: slab rate always.

~10 yr

Constant Duration

±10%

NAV / 1% Rate

5+ yr

Min Honest Horizon

Slab

Tax Rate (post-Apr 23)

Executive Summary · Page 2

Executive Summary · 6 Findings

Gilt Fund 10-Year Constant Duration is the sharpest debt mutual fund tool for rate-cycle participation. SEBI's only category with mechanical duration discipline — always ~10 years. Predictable behaviour (high volatility, high sensitivity) is the feature. Feb 2026: late cycle after 125 bps cuts. New entries should be limited and staged via SIP/STP.

Covers the wall-clock-vs-countdown-timer distinction (vs Target Maturity), mechanical rebalancing turnover costs, 10-year duration math (±10% per 1% rate), 2022-25 rate cycle history, Section 50AA tax, four common mistakes (short horizon, panic selling, late-cycle entry, government-backing confusion), and the seven retail questions.

Key Findings

Wall clock stuck at 10 — mechanical rebalancing.

SEBI requires this fund to always hold Macaulay duration ~10 years. The manager continuously sells 9-year bonds (drifted from 10) and buys 11-12 year bonds to maintain the average. Turnover costs typically 0.1-0.2% annually — modest but real. Unlike Target Maturity Funds (countdown timer), risk profile NEVER decreases.

±10% per 1% rate change — the sharpest mutual fund tool.

10-year duration × 1% rate change = ~10% NAV impact. RBI cuts 1% → NAV up ~10%. RBI hikes 1% → NAV down ~10%. ₹2L example: 1% rate cut → ₹2.20L. 1% rate rise → ₹1.80L. The volatility works both ways. No other SEBI category has this concentrated rate exposure with sovereign safety.

2022-25 history: -8% to -12% during hikes, +12-15% during cuts.

2022-23: RBI 4% → 6.5% (250 bps). 10-yr gilt funds: -8% to -12%. 2024-25: 6.5% → 5.25% (175 bps cumulative). 10-yr gilt funds: +12-15%. The fund behaves exactly as designed — sharp swings tracking rate direction. Confusion arises only when investors expect FD-like stability.

Different from Target Maturity Funds — risk profile never decreases.

Target Maturity Fund launched 2026 for 2036 maturity: starts at 10-year duration but naturally rolls down (10 → 5 → 0). Constant Duration: always 10. If your goal is 2031, Target Maturity 2031 makes sense (volatility decreases as goal approaches). If you want permanent rate exposure for tactical positioning, Constant Duration fits.

Tax: slab rate post-April 2023, identical to FDs. Deferral edge survives.

Section 50AA: all gains at slab rate regardless of holding period. No LTCG, no indexation. Pre-April 2023 grandfathered units redeemed post-July 23 2024: 12.5% LTCG after 24 months. Tax deferral remains structural — FD interest taxed annually on accrual; gilt gains taxed only at redemption. ~0.3-0.5% effective annual boost for 30%-slab over 5 years.

Direct plan mandatory: 0.5-0.8% Direct vs 0.8-1.2% Regular.

Gilt funds have no active stock-picking to justify distributor commissions. Direct plans 0.5-0.8%; Regular plans 0.8-1.2%. Over 5 yr on ₹10L: Direct ₹13.18L vs Regular ₹13.00L → ₹18K gap. Over 10 yr the gap compounds significantly. Use AMC website, Coin by Zerodha, Kuvera, MF Utility — no exceptions.

At A Glance

Metric	Value	Detail
Duration Mandate	~10 yr always	Mechanical
NAV / 1% Rate	±10%	Both ways
Turnover Cost	0.1-0.2%/yr	Rebalancing
Min Honest Horizon	5-7+ years	Through cycle
Recovery Time	2-4 yr after hike	Typical
Direct Expense	0.5-0.8%	Mandatory
Tax (post-Apr 2023)	Slab Rate	FD-identical
vs Target Maturity	Constant	Not countdown

Exhibit 01: 2-4 yr Recovery Pattern

Phase	RBI	10-yr Constant NAV
Hike (yr 1-2)	+250 bps	-8% to -12%
Stable (yr 2-3)	Hold	Flat to slightly +ve
Cut (yr 3-4)	-175 bps	+10% to +20%

Investors who held through the 2022-23 hiking cycle recovered fully during 2024-25 cuts. Panic-selling at -10% in 2023 = locking in 12% loss; missing 13% recovery in 2025. Discipline matters more than market timing.

The Opening · Page 3

The Opening

The 10-Year Constant Duration Gilt Fund is the sharpest rate-cycle tool the mutual fund industry offers in sovereign-quality wrapper. SEBI's mandate is unambiguous — at least 80% in G-Secs and SDLs, portfolio Macaulay duration always around 10 years. The manager mechanically sells bonds that have drifted to 9 years and buys 11-12 year bonds to maintain the average. The wall clock stays at 10 forever.

"A Gilt Fund (10-Year Constant Duration) is like a wall clock stuck at 10 o'clock — it always says 10. A Target Maturity Fund is a countdown timer that ticks from 10 to 0. Both start at the same duration, but their risk profiles diverge dramatically over time. The Constant Duration fund offers permanent, predictable rate exposure; the Target Maturity offers natural de-risking toward a goal date."
The Wall Clock Frame

The mathematics is uncompromising. 10-year duration × 1% rate change = ~10% NAV impact. RBI cuts repo by 1% → NAV up ~10%. RBI hikes by 1% → NAV down ~10%. ₹5L invested could become ₹4.30-4.40L in 2022 (rate hikes) or ₹5.50-5.80L in 2025 (rate cuts). The volatility works both ways. Government backing eliminates credit risk completely but does nothing for market risk.

Feb 2026 context. RBI at 5.25% after 125 bps cuts during 2025. Late-cycle position. Easy money from the 2024-25 cutting cycle largely captured. If you're entering now: limit to 5-10% of debt portfolio; use SIP/STP over 6-12 months; horizon 5-7+ years; accept that further 50 bps cuts deliver ~5% upside while a rate-hike pivot delivers -7% to -10% downside. The asymmetry has flipped from 2024.

The Honest Self-Check: can you tolerate ₹5L becoming ₹4.30L (14% paper loss) without panic-selling? Will you stay invested 5-7 years to recover? Do you understand this is a tactical positioning tool, not a stability product? If you cannot answer all three with conviction, this category is not for you. There's no shame in choosing regular Gilt Funds (3-7 year duration) or Short Duration Funds — they fit different risk profiles for different reasons.

Structure

Part I

How It Works, Duration Math, vs Other Categories

Part II

Tax, vs Target Maturity, vs FD / Dynamic Bond / Short Duration

Part III

When to Use, 4 Mistakes, Direct vs Regular

Part IV

The Verdict: Long-Duration Tool, Not Short-Term Safety

Use If

✓ 5-7+ year horizon

✓ Strong rate-cut conviction

✓ Tolerate 10-15% NAV decline

✓ Tactical 5-15% of debt

Do NOT Use If

✕ Short-term goals (<5 yr)

✕ Need capital protection

✕ First experience with NAV swings

✕ Set-and-forget retirement

Part I

How 10-Year Constant Duration Works, the Duration Math, and Comparison with Other Categories

The mechanics of continuous rebalancing to maintain Macaulay duration always ~10 years, the duration math that produces ±10% NAV swings per 1% rate change, and the critical distinction between this category and Target Maturity Funds (countdown timer vs wall clock).

Part I · Page 4

Two Types of Risk in Bond Funds

Risk Type	In Gilt 10-Yr
Credit Risk	~Zero (Government backing)
Duration Risk	Very High (~10 yr)

Critical reframe: Government backing eliminates default risk — it does NOT eliminate market risk. NAV will fluctuate dramatically based on rate movements. This is by design, not a defect.

Duration Math

Duration	1% Rate Move
1 year	±1%
5 years	±5%
10 years	±10%

₹2L Worked Example

Current 10-yr G-Sec yield: ~6.72% (Feb 2026)

RBI cuts 1% (6.5→5.5%): ₹2L → ₹2.20L

RBI hikes 1% (6.5→7.5%): ₹2L → ₹1.80L

Stable rates, hold 12 mo: ₹2L + accrual ~₹13K → ₹2.13L

Constant vs Target Maturity

Wall Clock vs Countdown Timer

10-Yr Constant Duration: always 10 years. Risk NEVER decreases. Mechanical rebalance.

Target Maturity Fund 2036: starts at 10 yr, rolls down to 0 by 2036. Risk DECREASES over time.

If your goal is 2031: Target Maturity 2031 wins (volatility decreases as goal approaches).
If you want permanent rate exposure for tactical positioning: Constant Duration fits.

vs Dynamic Bond Fund

Feature	10-Yr Constant	Dynamic Bond
Duration Changes	No — always 10	Yes — manager view
Tactical Calls	No	Yes
Predictability	High	Variable
Volatility	High & consistent	Depends on manager

Analogy: 10-Yr Constant is cruise control at 100 km/h. Dynamic Bond is a driver who speeds up or slows down based on the road ahead. You choose: rules-based predictability vs manager judgment.

vs Short Duration Fund

Feature	10-Yr Constant	Short Duration
Duration	~10 yr	1-3 yr
Rate Sensitivity	Very High	Low
Recovery After Hike	Years	Months
2-yr Goal?	No	Yes

Turnover Cost

Mechanical rebalancing — the manager continuously sells bonds drifting to 9 years and buys 11-12 year bonds. Turnover costs typically 0.1-0.2% annually. Modest but real. Factor into total expense calculation.

The architectural truth: 10-Year Constant Duration is the only debt mutual fund category designed for permanent high-volatility rate exposure. Target Maturity de-risks naturally; Dynamic Bond rotates manager-judgment; this stays at maximum sensitivity always. Pick it deliberately, not accidentally.

Part II

Tax (Section 50AA), and Comparison with Target Maturity / FD / Other Debt Funds

Why Section 50AA made gilt funds tax-identical to FDs at slab rate, why Target Maturity Funds beat Constant Duration for goal-based investing, and the structural distinctions that determine when this category earns its place over Dynamic Bond, Short Duration, or Fixed Deposits.

Part II · Page 6

Tax — Post-April 2023

Slab Rate Always — Section 50AA

All capital gains taxed at slab rate regardless of holding period. No indexation. No LTCG.

Example: ₹8L invested May 2023, sold March 2027 (47 mo) at ₹10L. Gain ₹2L.
30% slab → tax ₹60K. 20% → ₹40K. 5% → ₹10K.

The 36-month LTCG benefit that existed pre-April 2023 has been completely eliminated. Tax-identical to FD interest.

Pre-April 2023 Grandfathered

Holding / Sale Window	Tax
>36 mo, sold post-Jul 23 2024	12.5% LTCG (no indexation)
>36 mo, sold pre-Jul 23 2024	20% with indexation (or 12.5% — lower)
≤36 mo	Slab rate (STCG)

FD vs 10-Yr Constant (Post-April 2023)

Equal tax rate at slab. Only edge: tax deferral (gilt fund tax at redemption vs FD annual accrual). For 30%-slab over 5 years on ₹10L: ~₹28K boost from compounding the deferred tax. Modest but real.

NRI

30% TDS plus surcharge/cess on gains at redemption. DTAA via Form 10F + tax residency certificate.

vs Target Maturity Fund

Feature	10-Yr Constant	Target Maturity
Risk Today	10 yr duration	10 yr (if launched)
Risk in 5 yr	Still 10 yr	5 yr
At Maturity	Still 10 yr	0 yr
Best For	Tactical	Goal-based

vs Fixed Deposit

Feature	10-Yr Constant	5-yr FD
Returns	Variable, ±10% swings	7% guaranteed
Capital Protection	No	DICGC ≤ ₹5L
Liquidity	Anytime at NAV	Penalty
Best For	5+ yr rate bet	Stability

Portfolio Position

Approach	Allocation
Conservative	0-5% of debt
Moderate (rate conviction)	5-15% of debt
Aggressive	15-20% max

Not recommended as primary or only debt holding. You need stability-focused funds (Liquid, Short Duration) too.

The decision framework: if your horizon is 5+ years AND you have rate-cut conviction AND you can tolerate 10-15% NAV declines AND you've answered yes to all three honestly — allocate 5-15%. If any one is no, this isn't your category.

Part III

When to Use This Fund, Four Common Mistakes, and Direct vs Regular Plans

The four-question decision framework (horizon, volatility, purpose, rate view), the four mistakes that turn rate-cycle volatility into permanent losses (short horizon, panic selling, late-cycle entry, government-backing confusion), and why Direct plans are essentially mandatory for this category.

Part III · Page 8

4-Question Decision Framework

Horizon Check

Is my horizon 5+ years? Yes → proceed. No → stop. Use Short Duration / FDs instead.

Volatility Comfort

Can I tolerate ₹5L becoming ₹4.30L temporarily? Yes → proceed. No → stop.

Purpose Check

Duration exposure / rate-cycle participation → fits. Stable income / capital protection → does not fit.

Rate View (Optional)

Rates expected to fall or stabilise? May outperform. Unsure? Reconsider or minimise allocation.

Direct vs Regular

Plan	Expense	5-yr Value ₹10L
Direct	0.5-0.8%	₹13.18L
Regular	0.8-1.2%	₹13.00L
5-yr Gap	0.3-0.5%	₹18K

10-yr gap compounds significantly. Always Direct via AMC website, Coin, Kuvera, MF Utility. No exceptions for a passive sovereign exposure product.

Sample Allocation

Portfolio ₹50L	Allocation
Total Debt	₹15L (30%)
10-Yr Constant	₹75K - ₹2.5L (5-15% of debt)
Rest of Debt	FD/PPF/Short/Corp Bond

Four Common Mistakes

Using for Short-Term Goals

"Need money in 18 months, ₹4L in 10-yr constant gilt because govt-backed." Rates could rise; NAV could be -10%; forced to withdraw at ₹3.60L instead of ₹4L.

Confusing Govt Backing with Stability

"It's government-backed so can't go down." Govt backing = no default risk, not no price fluctuation. Bond prices move daily based on market rates.

Panic-Selling During Hikes

₹10L → ₹8.80L during 2022 hikes. Panic exit. Locked in 12% loss. If held to 2024-25 cuts, recovered to ₹10.50L. Cycle reversed; you didn't.

Entering Only After Cuts Begin

Wait for first cut announcement → rush in → most upside already priced in. Better timing: when rates stable or near peak (though hard to predict).

Already Holding Negative Returns?

Diagnosis-First Playbook

Rate-rise driven decline? Normal duration behaviour. Hold if horizon >3 yr. Cycle will reverse.

Horizon shrunk to <1 yr? Exit reluctantly; lesson learned about matching tool to timeline.

Risk tolerance changed? Exit; move to lower-volatility category. Sleep matters more than residual upside.

Typical recovery: 8-15% decline → flat 1-2 yr → 10-20%+ recovery during next cut cycle. Total cycle ~3-4 years.

Feb 2026 Specific Action

Status	Action
Hold from 2023-24	HOLD, profits captured
Fresh entry	5-10% of debt via STP
Lump-sum at 5.25%	High asymmetric risk

The 30-second pitch: mutual fund holding only government bonds, always 10-year sensitivity, performs strongly when rates fall, drops 10-15% when rates rise, best for 5+ year investors who want rate-cycle gains. Long-duration tool, not short-term safety.

Part IV

The Verdict

Permanent rate exposure. Patient investors only.

Part IV: The Verdict · Page 10

30-Second Summary

The 10-Year Constant Duration Gilt Fund is the sharpest rate-cycle tool in mutual funds with sovereign safety. Mechanical rebalancing maintains Macaulay duration ~10 years always — wall clock stuck at 10, never a countdown timer. ±10% NAV swings per 1% rate change. 2022-23 hiking cycle delivered -8% to -12%; 2024-25 cutting cycle delivered +12-15%. The volatility is the feature, not the bug.

Feb 2026: late-cycle position after 125 bps cuts during 2025. Easy money largely captured. Tax under Section 50AA is identical to FDs — slab rate always. Tax-deferral edge survives at ~0.3-0.5% per year for 30%-slab. Direct plans mandatory (0.5-0.8% vs Regular 0.8-1.2%). Suitable only with 5+ year honest horizon, rate-cycle conviction, tolerance for 10-15% NAV declines, and limited allocation (5-15% of debt).

"A Gilt Fund (10-Year Constant Duration) is like a wall clock stuck at 10 — predictably high-volatility, always rate-sensitive, never de-risking. It is not a stability product. It is not an FD substitute. It is a long-duration tactical tool. The investors who succeed with this category are those who understand this completely before investing and have the patience to hold through 2-4 year cycles."
The Final Orientation

The Bottom Line: Use this fund for 5-7+ year tactical rate-cycle positioning, alongside Liquid + Short Duration core and Corporate Bond / PPF for stability. Don't use for short-term goals, capital protection, first-time NAV-volatility experience, or set-and-forget retirement. Direct plan, 5-15% of debt allocation, horizon-matched honesty, rate-cycle conviction are the four selection criteria. Feb 2026 specifically — limit fresh entry to 5-10% via STP or wait for next rate peak.

ADWIZR · June 2026

Decision Rules

Use Correctly As

✓ 5-7+ year horizon

✓ Direct plan, Growth

✓ Strong rate-cut conviction

✓ 5-15% of debt allocation

Misuse Destroys Value

✕ <5 year horizon

✕ FD substitute

✕ Set-and-forget retirement

✕ First debt fund experience

Triggers to Reassess

When to Open the Factsheet Again

(1) Rate cycle reverses (cuts → pause → hikes anticipated) — book profits, reduce. (2) Inflation breaches 5.5% — RBI hike risk; consider exit. (3) Horizon shrinks below 3 years — switch to Short Duration. (4) Expense ratio rises above 0.8% (Direct) — switch peer.

10 yr

Constant duration

Wall clock

±10%

NAV / 1% rate

Both ways

5+ yr

Honest horizon

Full cycle

Investor FAQ

Questions Indian Investors Ask

Seven questions, answered directly.

Investor FAQ · Page 12

Frequently Asked Questions

Q1 Can I lose money even though it's government-backed?

Yes. Government-backed means the government will repay bonds at maturity — it does NOT protect from price fluctuations. If you sell when NAV is down (due to rising rates), you book a loss. ₹4L invested, NAV falls 12%, sell at ₹3.52L = ₹48K real loss.

Q2 Should I invest if I need money in 2 years?

No. These funds are highly sensitive to interest rate changes. A 2-year horizon is too short to ride out potential NAV drops. Use Liquid Funds, Ultra Short Duration Funds, or Fixed Deposits for 2-year goals.

Q3 How different from regular Gilt Fund?

Regular Gilt: manager-flex duration (3-7 yr typical), can shift from 8 yr to 4 yr based on view. 10-Yr Constant: ALWAYS ~10 yr, rules-based mechanical rebalancing. Regular = active; Constant = passive on duration.

Q4 When is the best time to invest?

Ideally when rates are high or near peak. Timing is difficult — use SIP for 5+ year horizons regardless of timing. If rates rise after you invest, SIPs buy at lower NAVs, averaging cost. Feb 2026 is late-cycle, so prefer STP over lump sum.

Q5 What happens during RBI rate cuts?

Bond prices rise when rates fall. With 10-yr duration, this fund benefits significantly. 2019-20 example: ₹2L could have become ₹2.25-2.30L during cutting cycle. 2024-25: similar pattern. The amplification is the point of choosing this category.

Q6 Suitable for retirees seeking regular income?

Not ideal. NAV volatility can be stressful for retirees. Better: Short-duration funds with SWP, Conservative Hybrid Funds, SCSS (8.2%), or FD ladders. Use 10-Yr Constant only if part of larger portfolio with sufficient stability bucket and you're emotionally comfortable with swings.

Q7 How do I verify 10-year duration?

Check fund's monthly factsheet on AMC website. Look for 'Macaulay Duration' or 'Modified Duration' — should be close to 10 years (typically 9.5-10.5). SEBI regulations mandate this disclosure.

Key Terms & Definitions

Gilt Fund (10-Year Constant Duration)

A SEBI-regulated open-ended debt mutual fund mandated to invest at least 80% in G-Secs and SDLs while continuously maintaining portfolio Macaulay duration around 10 years. The wall clock stuck at 10 — risk profile never decreases.

Mechanical Rebalancing

The continuous portfolio adjustment required to maintain ~10-year duration. Manager sells bonds that have drifted to 9 years and buys 11-12 year bonds. Turnover costs 0.1-0.2% annually.

Duration Risk (Modified Duration)

The percentage change in NAV per 1% change in interest rates. For 10-Year Constant Duration, modified duration is ~9-10 — producing ±10% NAV swings per 1% rate change. The category's defining sensitivity.

Wall Clock vs Countdown Timer

The conceptual distinction between 10-Year Constant Duration (always 10 years, risk constant) and Target Maturity Fund (starts at 10, rolls down to 0 by target year, risk decreases). Different tools for different jobs.

Section 50AA

Finance Act 2023 provision: for units of debt mutual funds (including 10-Yr Constant Duration) bought on or after April 1, 2023, all gains are taxed at slab rate regardless of holding period. Eliminated the LTCG advantage.

Tax-Deferral Edge

The structural advantage of debt funds over FDs at identical slab tax rates: mutual fund tax is paid only at redemption, allowing capital to compound until exit. FD interest taxed annually on accrual. Worth ~0.3-0.5% per year for 30%-slab investors over 5+ years.