Rho (ρ)
Interest-rate sensitivity — the quietest greek, and why it rarely drives a weekly trade.
The change in an option’s price for a 1% change in the risk-free interest rate.
Overview
Rho measures how an option’s price responds to a change in the risk-free interest rate. Higher rates raise the cost of carry embedded in an option, lifting call values and pressuring put values (and vice-versa).
Calls have positive rho; puts have negative rho. Rho grows with time to expiry and with how deep in-the-money the option is — so it matters for long-dated (LEAPS-style) positions and is almost negligible for the weekly and monthly expiries that dominate Indian index trading.
For most retail option trades, rho is the greek you can safely check last: rate moves are small and slow relative to the daily swings of delta, gamma, theta and vega.
A plain-language example
You hold a long-dated NIFTY call with rho +50.
The central bank surprises with a 1% rate hike: the option gains roughly ₹50 from rho alone, before any move in the index.
The same rate cut would cost that call about ₹50. For a weekly option, rho might be a rupee or two — swamped by the other greeks, which is why traders usually ignore it there.
Calls: positive rho · Puts: negative rho · Grows with time to expiry and moneyness · Tiny for weekly/monthly options.
Buyers vs sellers
If you buy the option
Long calls are +rho; long puts are −rho.
If you sell the option
Short calls are −rho; short puts are +rho.
What moves Rho
| When… | Effect on Rho |
|---|---|
| More time to expiry | Rho grows — carry has longer to compound |
| Deeper in-the-money | Rho magnitude increases (more notional carried) |
| Short-dated option | Rho is negligible — the usual case for weeklies |
| Rate hike / cut | Lifts call values / lifts put values respectively |
Rho at a glance
How traders use it
- Only long-dated positions (multi-month or LEAPS-style) carry meaningful rho — check it there, ignore it on weeklies.
- In a rate-hiking cycle, long calls and short puts get a small structural tailwind from rho; long puts and short calls face a small headwind.
- Rho is the reason put-call parity ties call and put prices together through the cost of carry.
Watch out for
- Do not over-weight rho on short-dated index options — its effect is dwarfed by delta, gamma, theta and vega.
- Rho assumes a parallel shift in the rate used to price the option; real-world curves move unevenly.
See Rho on a live position
Open the Strategy Builder, add a leg, and hover the Rho row in the Greeks tab to watch it update in real time.
Educational content only — not investment advice. All values are illustrative and do not reflect live quotes. Options carry significant risk; consult a registered adviser before trading.