📚 PASS Investment Adviser (Level 1) Difficulty: Intermediate ℹ️ Info   ~5 min read
📌 Chapter 9.9 — Introduction to Government Debt Market

Imagine you are a treasury analyst at a mid-sized brokerage, reviewing a client’s request to allocate liquidity into a 364-day Treasury Bill (T-Bill). The client, focused on yield maximization, asks how a paper issued at ₹94.50 and redeemed at ₹100 represents a competitive return compared to a bank fixed deposit. To provide a professional assessment, you must look past the simple price appreciation and calculate the annualized discount yield. This figure allows you to compare disparate instruments with different maturities on a standardized, annualized basis.

In the Indian money market, discount instruments like T-Bills and Cash Management Bills (CMBs) do not pay periodic coupons. Instead, the investor’s return is the difference between the face value and the purchase price. Because these instruments are short-term, the calculation utilizes a simple interest convention based on a 365-day year. This calculation is vital because it converts the absolute price gain into a percentage rate, which is the universal language of portfolio performance and benchmark comparison.

To calculate the discount yield, use the formula: [(Face Value - Price) / Face Value] * (365 / Days to Maturity). If you purchase a 364-day T-Bill for ₹95.00 that matures at ₹100, the calculation is (5 / 100) * (365 / 364), resulting in a yield of approximately 5.01%. This metric is essential for liquidity management; it allows a fund manager to decide whether to park surplus cash in a sovereign T-Bill or move it into a short-term commercial paper of similar duration, adjusting for the credit risk premium.

Mastering this calculation changes how you present investment strategies to institutional clients. Rather than quoting absolute price points, you communicate in terms of annualized yields, which facilitates easier integration into performance dashboards. It also informs your understanding of the Reserve Bank of India’s monetary policy; by tracking how these yields move in response to liquidity windows or repo rate changes, you gain a forward-looking perspective on the cost of debt across the broader economy.

Nuance

⚠️ Nuance
A common professional pitfall is confusing the ‘Discount Yield’ with the ‘Bond Equivalent Yield’ (BEY). The discount yield uses the face value as the denominator, which inherently underestimates the actual realized return of the investment relative to the capital deployed. Analysts who rely solely on the discount yield when comparing T-Bills to coupon-bearing bonds will consistently misjudge the relative attractiveness of the T-Bill, as the BEY is always higher than the discount yield.

Check Your Understanding

Practice Question 1

An investor purchases a 182-day T-Bill with a face value of ₹10,000 at a price of ₹9,750. What is the annualized discount yield of this instrument (using a 365-day year)?

Practice Question 2

Why is the discount yield of a T-Bill typically lower than its bond equivalent yield?

This is a companion read for Section 9.9 — Introduction to Government Debt Market from PASS Investment Adviser (Level 1) by Akhilesh Gururani, available on Amazon Kindle.

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