Chapter 3: Exchange Traded Interest Rate Futures

3.1 Concept and Design of Exchange Traded Interest Rate Futures

An Exchange Traded Interest Rate Futures (ETIRF) contract is a standardized financial futures contract legally traded on recognized stock exchanges (such as NSE, BSE, and MSEI) within the Currency Derivatives Segment. It obligates the buyer to purchase and the seller to deliver (or cash-settle) a specified debt instrument or cash equivalent at a fixed price on a predetermined terminal date.

ETIRFs eliminate bilateral counterparty risk through the legal mechanism of novation, whereby the Clearing Corporation interposes itself as the buyer to every seller and seller to every buyer.

3.2 Payoff Profiles for Futures Contracts

Futures contracts possess linear, symmetrical payoff structures. Unlike options, neither party has the discretion to abandon the contract.

Profit ^                                         Profit ^
       |             / Long Futures                     | \            Short Futures
       |            /                                   |  \
       |           /                                    |   \
  -----+----------/----------> Price               -----+----\----------> Price
       |         /                                      |     \
       |        /                                       |      \
       v                                                v

1. Long Futures (Buyer): $$\text{Payoff} = (\text{Futures Settlement Price} - \text{Futures Entry Price}) \times \text{Contract Multiplier}$$
   • Profits when bond prices rise (which corresponds to falling interest rates/yields).
   • Suffers losses when bond prices drop (rising interest rates/yields).
2. Short Futures (Seller): $$\text{Payoff} = (\text{Futures Entry Price} - \text{Futures Settlement Price}) \times \text{Contract Multiplier}$$
   • Profits when bond prices fall (rising interest rates/yields).
   • Suffers losses when bond prices rise (falling interest rates/yields).

3.3 Contract Specifications of ETIRF in India

The SEBI regulatory framework, in consultation with the RBI, provides standardized contract architectures for sovereign bond futures:

3.4 Lot Size, Tick Size, and Value per Tick Change

The relationship between lot size, price quotation, and tick value is central to risk management and position sizing:

$$\text{Tick Value} = \text{Tick Size} \times \frac{\text{Contract Face Value}}{100}$$ $$\text{Tick Value} = ₹0.0025 \times \frac{₹2,00,000}{100} = ₹0.0025 \times 2,000 = \mathbf{₹5.00}$$

Operational Insight: Every price movement of 1 paisa (₹0.01) represents 4 ticks, generating a financial impact of: $$\text{P&L per Paisa} = 4 \times ₹5.00 = ₹20.00 \text{ per contract}$$ A 1-Rupee movement in bond price generates: $$\text{P&L per Rupee} = 100 \times ₹20.00 = ₹2,000 \text{ per contract}$$

3.5 Rationale for Introducing ETIRF in India

Prior to exchange-traded futures, market participants managed interest rate risk primarily through OTC swaps (OIS) or by actively trading physical debt in the secondary cash market. Exchange-traded futures introduced several systemic enhancements:

1. Democratization of Market Access: Provided a standardized, transparent platform for corporate treasuries, non-scheduled banks, mutual funds, and retail investors who lacked access to the interbank OTC market.
2. Mitigation of Systemic Counterparty Risk: All transactions are guaranteed by SEBI-regulated Clearing Corporations, backed by multi-tiered Core Settlement Guarantee Funds (Core SGF).
3. Capital Efficiency: Participants can hedge large balance sheet exposures using a fraction of the capital via upfront margin deposits (SPAN and ELM) without incurring asset-liability expansion.
4. Enhanced Sovereign Debt Liquidity: Active futures trading tightens bid-ask spreads in the underlying spot G-Sec market through continuous basis trading and arbitrage.

3.6 Comparison: ETIRF vs OTC Forward Rate Agreements (FRAs)

3.7 Pricing of Interest Rate Futures and Deliverable Basket Mechanics

1. Cost of Carry Valuation Model

The theoretical futures price of a bond equals the spot bond price compounded at the financing repo rate, minus the future value of coupon cash flows earned prior to expiration:

$$F = [S_0 - PV(\text{Coupons})] \cdot (1 + r)^T$$ Or in clean price continuous compounding terms: $$F = (S_0 - I) \cdot e^{r \cdot T}$$ Where:

• $S_0$ is the current spot dirty price of the underlying bond
• $I$ is the present value of coupon cash flows received during the contract life
• $r$ is the risk-free financing borrowing rate (repo rate)
• $T$ is the time to futures contract expiration

2. The Conversion Factor (CF) System

In physically delivered bond futures (such as the standard 10-year G-Sec contract), multiple government securities with varying coupon rates and maturity dates are eligible for delivery. To create parity among disparate deliverable bonds, the exchange assigns each bond a Conversion Factor (CF).

The Conversion Factor represents the theoretical clean price of ₹1 face value of the deliverable bond on the first day of the delivery month, evaluated to yield a standardized notional coupon of 6.00% per annum (payable semi-annually):

• A bond with a coupon greater than 6.00% has a $\text{CF} > 1.0000$.
• A bond with a coupon less than 6.00% has a $\text{CF} < 1.0000$.
• A bond with a coupon exactly equal to 6.00% has a $\text{CF} = 1.0000$.

3. Invoice Price Formula

When a short position holder delivers a bond to settle a futures contract, the buyer must pay the Invoice Price:

$$\text{Invoice Amount} = \left[ (\text{Futures Settlement Price} \times \text{CF}) + \text{Accrued Interest} \right] \times \frac{\text{Contract Face Value}}{100}$$

4. Cheapest-to-Deliver (CTD) Bond Selection

The seller of the futures contract holds the delivery option and will logically select the bond that minimizes delivery costs or maximizes delivery profit. This bond is designated as the Cheapest-to-Deliver (CTD).

The CTD bond can be determined through two equivalent methodologies:

1. Net Basis Minimization: $$\text{Gross Basis} = \text{Spot Clean Price} - \text{Futures Price}$$ $$\text{Net Basis} = \text{Spot Clean Price} - (\text{Futures Price} \times \text{CF}) - \text{Net Carry}$$ The bond with the lowest Net Basis is the CTD bond.

2. Implied Repo Rate (IRR) Maximization: The Implied Repo Rate is the annualized rate of return realized by purchasing a deliverable spot bond, financing it, selling the futures contract, and delivering the bond at contract expiry: $$\text{IRR} = \frac{(\text{Futures Price} \times \text{CF}) + \text{Accrued Interest at Delivery} - \text{Spot Purchase Dirty Price} + \text{Coupons Received}}{\text{Spot Purchase Dirty Price}} \times \frac{365}{\text{Days to Delivery}}$$ The deliverable bond offering the highest Implied Repo Rate is the CTD bond.