Debt Funds — Medium, Long Duration, Dynamic Bond, Gilt
Definition
Under SEBI categorization, medium-to-long duration debt fund categories include: Medium Duration Fund (Macaulay duration 3-4 years), Medium to Long Duration Fund (4-7 years), Long Duration Fund (7+ years), Dynamic Bond Fund (no duration restriction — fund manager actively manages duration), Corporate Bond Fund (minimum 80% in AA+ and above rated corporate bonds), Credit Risk Fund (minimum 65% in below AA-rated corporate bonds), Banking & PSU Fund (minimum 80% in debt instruments of banks, PSUs, and Public Financial Institutions), Gilt Fund (minimum 80% in government securities), Gilt Fund with 10-year Constant Duration (minimum 80% in G-Secs with portfolio Macaulay duration of 10 years), and Floater Fund (minimum 65% in floating rate instruments).
In Simple Words
Over the past two decades, medium-to-long duration debt funds have been the source of both the biggest gains and the most painful losses in fixed income. Understanding each category from a practical perspective is essential. Medium Duration (3-4 years) and Medium to Long Duration (4-7 years) funds are the workhorses for investors with 3-5 year horizons. They invest in a mix of corporate bonds and government securities. The return potential is higher than short-duration funds, but so is the sensitivity to RBI rate actions. When the RBI was cutting rates from 8% to 4% between 2019-2020, medium duration funds delivered 9-11% returns. When rates reversed upward in 2022, the same funds saw temporary NAV erosion. Long Duration Funds (7+ years) are the most sensitive to interest rate changes. These are essentially a pure play on the interest rate cycle. When rates fall, long duration funds deliver equity-like returns. When rates rise, they can give negative returns for extended periods. These are suitable only for sophisticated investors who have a view on the rate cycle. Dynamic Bond Funds are particularly noteworthy — the fund manager has complete freedom to shift between short and long duration based on their rate outlook. If they expect rate cuts, they extend duration to 7-8 years. If they expect rate hikes, they compress to 1-2 years. The success depends entirely on the fund manager's ability to read the interest rate cycle correctly. An important nuance often overlooked about Credit Risk Funds is that they were the source of the biggest debt fund crisis in India. Franklin Templeton's six debt fund schemes (including credit risk) were wound up in April 2020 because the underlying corporate bonds defaulted or became illiquid. Credit Risk Funds invest 65%+ in below AA-rated bonds — these are companies with weaker credit profiles that pay higher interest. The higher yield is compensation for the higher default risk. After the Franklin episode, most experienced distributors recommend Credit Risk Funds only for investors who truly understand and accept the possibility of permanent capital loss. Corporate Bond Funds (min 80% in AA+ and above) are the safer alternative — they stick to high-quality issuers. Banking & PSU Funds are even safer as they invest in bank and government-backed entity debt. Gilt Funds are the purest expression of interest rate risk — they invest 80%+ in government securities with zero credit risk (sovereign guarantee). The Gilt Fund with 10-year Constant Duration is designed for investors who want consistent exposure to long-term government bonds. Floater Funds invest 65%+ in floating rate instruments — their coupons adjust with market rates, making them relatively immune to interest rate changes.
Real-Life Scenario
Consider the case of Mohan, a 55-year-old businessman in Pune, who had ₹1 crore to invest conservatively for 5 years. A financial advisor structured his debt portfolio as follows: ₹30 lakh in Banking & PSU Fund (e.g., IDFC Banking & PSU Debt Fund): This fund invests 80%+ in bonds from SBI, HDFC Bank, PFC, REC — all government-backed or top-rated banks. The credit risk is minimal, with expected returns of 6.5-7.5% over 3-5 years. ₹25 lakh in Corporate Bond Fund (e.g., HDFC Corporate Bond Fund): This invests only in AA+ and above rated corporate bonds — companies like Reliance Industries, HDFC Ltd, and Bajaj Finance. Slightly higher yield than Banking & PSU, still very high credit quality. ₹20 lakh in Dynamic Bond Fund (e.g., ICICI Pru All Seasons Bond Fund): The fund manager has flexibility to adjust duration based on rate outlook. In 2019 when rates were being cut, this fund delivered 12% by extending duration. When rates started rising in 2022, the manager shortened duration to protect capital. ₹15 lakh in Gilt Fund (e.g., SBI Magnum Gilt Fund): Zero credit risk — 100% government securities. The returns depend on the interest rate cycle, but there is no risk of loss due to corporate default. ₹10 lakh in Floater Fund (e.g., HDFC Floating Rate Debt Fund): This serves as a hedge against rising rates. When other debt funds suffer from rate hikes, floater funds actually benefit because their coupon rates adjust upward. Notably, Credit Risk Funds were deliberately excluded from Mohan's portfolio. The Franklin Templeton episode serves as a cautionary tale: in April 2020, six Franklin debt schemes were shut overnight. Investors with ₹25,000 crore could not access their money for over two years. The extra 1-2% yield from lower-rated bonds does not justify the risk of sleepless nights, especially for retirement corpus.
Key Points to Remember
Formula
Credit Risk Premium = Yield on Corporate Bond - Yield on Government Bond of similar maturity Example: AAA Corporate Bond yield: 7.5% 10-year G-Sec yield: 7.0% Credit spread = 0.5% (50 basis points) A-rated Corporate Bond yield: 9.5% 10-year G-Sec yield: 7.0% Credit spread = 2.5% (250 basis points) The higher spread for A-rated bonds reflects the higher default risk. Credit Risk Funds earn this spread but also bear the risk of default.
Numerical Example
Seema invests ₹20,00,000 in different debt fund categories. Let us see the impact of a 1% interest rate hike: Medium Duration Fund (duration 3.5 years): NAV impact ≈ -3.5 x 1% = -3.5% Temporary loss = ₹20,00,000 x 3.5% = ₹70,000 Long Duration Fund (duration 8 years): NAV impact ≈ -8 x 1% = -8% Temporary loss = ₹20,00,000 x 8% = ₹1,60,000 Gilt Fund 10-year Constant Duration (duration 10 years): NAV impact ≈ -10 x 1% = -10% Temporary loss = ₹20,00,000 x 10% = ₹2,00,000 Floater Fund (duration ~0.3 years): NAV impact ≈ -0.3 x 1% = -0.3% Temporary loss = ₹20,00,000 x 0.3% = ₹6,000 Plus, the coupon resets higher, benefiting the fund going forward This illustrates a key principle for debt fund investing: Rate hike coming? Reduce duration. Rate cut expected? Extend duration. Cannot predict? Use Dynamic Bond.
Frequently Asked Questions
Test Your Knowledge
4 questions to check your understanding
A Credit Risk Fund must invest a minimum of ___% in corporate bonds rated below AA.
Summary Notes
Medium (3-4Y) → Medium to Long (4-7Y) → Long (7Y+) → each step up means more interest rate sensitivity
Dynamic Bond = no duration restriction — fund manager reads the rate cycle and adjusts; success depends on manager skill
Corporate Bond (AA+ above) is the safe corporate play; Credit Risk (below AA) is high-yield-high-risk — remember Franklin Templeton
Gilt Fund = zero credit risk (government guarantee) but full interest rate risk; 10-year constant duration variant is the most volatile
Floater Fund benefits from rising rates — floating coupons reset higher when rates increase, making it a natural rate-hike hedge