Introductory Context
"Duration-neutral fixed income arbitrage exploiting rotations in the 2Y-10Y sovereign G-Sec and MIBOR Overnight Indexed Swap (OIS) yield curve."
Yield Curve Shape Arbitrage: Steepener vs Flattener Regimes
Interest rate yield curves do not shift only in parallel; they undergo dramatic changes in slope (steepening and flattening) driven by Reserve Bank of India (RBI) Monetary Policy cycles, systemic liquidity conditions (LAF deficit/surplus), and government borrowing calendars. Quantitative fixed income desks trade these structural curve rotations using Duration-Neutral Curve Arbitrage.
Executed when RBI begins rate cuts or infuses aggressive liquidity. The short end (2Y/5Y yields) collapses faster than the long end (10Y/14Y yields). The desk buys front-end bonds and sells/hedges long-end bonds in exact DV01-neutral ratios.
Executed during RBI rate hike cycles or high inflation prints. Front-end yields rise rapidly while long-term growth expectations cool, compressing the 2Y-10Y or 5Y-10Y yield spread.
• The Curve Arbitrage Rule in One Sentence
Monitor the historical Z-score of the 2Y-10Y G-Sec or Overnight Indexed Swap (OIS) slope; enter DV01-neutral curve steepeners when the slope is abnormally compressed (< -1.5σ) and flatteners when the slope is stretched (> +1.5σ).
Mathematical Formulation: DV01 Neutrality & Hedge Ratios
To eliminate outright market direction risk (parallel shifts in yields), the position weights must satisfy strict Dollar Duration (DV01) Neutrality. Let DV01front and DV01long represent the price sensitivity to a 1 basis point change in yield:
For a DV01-neutral pair holding notional Nfront and Nlong:
The Hedge Ratio (HR) of front-end face value per unit of long-end face value is:
- Example: A 10-Year G-Sec has DV01 = ₹0.068 per ₹100 face value (Modified Duration ≈ 6.8). A 2-Year G-Sec has DV01 = ₹0.018 per ₹100 face value (Modified Duration ≈ 1.8).
- Hedge Ratio: 0.068 / 0.018 = 3.78. To execute a curve steepener, the desk buys ₹37.8 Crores face value of 2-Year G-Secs for every ₹10 Crores face value short of 10-Year G-Secs (or equivalent IRF futures).
- Outcome: If all interest rates rise uniformly by 50 bps, net P&L is zero. If the yield curve steepens by 15 bps (2Y yields fall by 10 bps, 10Y yields rise by 5 bps), the desk captures pure slope profits on both legs.
Instruments in India: G-Secs, OIS, and Interest Rate Futures (IRF)
In Indian financial markets, curve arbitrage is executed via three primary institutional instruments:
- Overnight Indexed Swaps (MIBOR OIS): The most liquid OTC derivatives curve in India, trading 1-year, 2-year, 3-year, and 5-year tenors benchmarked against the daily Mumbai Interbank Outright Rate (MIBOR).
- CCIL Sovereign Benchmark G-Secs: Cash market outright trades executed on the NDS-OM matching engine with settlement via the Clearing Corporation of India (CCIL).
- NSE 10-Year & 5-Year Bond Futures (IRF): Standardized exchange-traded contracts allowing leverage and effortless short positioning without borrowing physical bonds in the repo market.