What the option Greeks mean for a hedged weekly options position

The option Greeks describe how an option's price reacts when something in the market changes. For a hedged weekly options position on NIFTY or SENSEX, they explain most of the day-to-day movement in profit and loss. This article covers the four main Greeks, what a hedge does to each, and why they change as expiry gets closer.

What a hedged weekly position is

A weekly option trades for a few days and expires on a fixed weekday. A hedged position combines sold options with bought options. The bought options cap how much the position can lose if the index moves sharply; the protection is paid for out of the premium collected on the sold options.

Each option in the position has its own Greeks. The Greeks of the whole position are simply the sum of the Greeks of every leg, each multiplied by the number of contracts and by whether the leg is bought or sold.

Delta: sensitivity to the index level

Delta measures how much an option's price changes when the underlying index moves by one point. A call option has a delta between 0 and 1; a put option has a delta between 0 and −1. An option far away from the current index level has a delta close to zero, and an option at the current level has a delta of roughly 0.5 in size.

For a position, delta tells you which way the index needs to move for the position to gain or lose, and roughly by how much. A position with a delta near zero is described as delta-neutral: small moves in the index barely change its value. Delta-neutral does not mean risk-free. It only describes the first, small move.

Gamma: how fast delta changes

Gamma measures how much delta itself changes when the index moves by one point. It is highest for options whose strike is close to the current index level, and it grows sharply as expiry approaches.

Gamma is why a position that looked balanced in the morning can become strongly directional by the afternoon. When a position has negative gamma, which is typical when options are sold, every move in the index pushes delta in the wrong direction: the position loses more the further the index travels. Bought options carry positive gamma, which is exactly what a hedge contributes. The hedge reduces the position's overall negative gamma, especially for large moves.

Theta: time decay

Theta measures how much an option's price falls with the passage of one day, all else being equal. Option buyers pay theta; option sellers earn it.

Time decay is not spread evenly across an option's life. It is slow when expiry is far away and speeds up in the last few days, with the steepest decay on the final day. This is the main reason weekly options attract sellers: much of an option's remaining time value can disappear within days. A hedge gives some of that back, because the bought options also lose value to time decay.

Vega: sensitivity to volatility

Vega measures how much an option's price changes when implied volatility, the market's expectation of future movement, changes by one percentage point. Bought options gain when implied volatility rises; sold options lose.

Implied volatility often rises around events such as policy announcements or global market shocks, and falls once they pass. For a position that is net short options, rising volatility can produce a loss on a day when the index barely moves. Vega is smaller for weekly options than monthly ones, but it does not disappear.

How the hedge changes the picture

Putting the four Greeks together, a hedge changes a short options position in a few predictable ways:

• It reduces the maximum loss from a large move, because the bought options gain as the move continues.
• It lowers negative gamma, so losses build more slowly in a fast market.
• It reduces net theta, because the hedge itself decays. The position earns less from the passage of time than an unhedged one.
• It reduces net vega, so a spike in volatility hurts less.

None of this removes risk. Gaps at the open, sudden volatility spikes and execution slippage can still produce losses, and a hedged position can lose on many days in a row.

Why expiry week changes everything

As expiry approaches, the Greeks of short-dated options become extreme. Gamma near the current index level becomes very large, so small index moves cause large swings in delta and in P&L. Theta also accelerates, and options far from the index level lose almost all their value.

This is why the daily P&L of a weekly options position often looks very different on expiry day than earlier in the week. Our article on how weekly expiry works for NIFTY and SENSEX options explains what happens on that day in more detail.

Reading the Greeks alongside a P&L ledger

The Greeks describe how a position should react to the next move; a daily P&L ledger records what actually happened. Reading both together helps explain results. A loss on a quiet day often points to rising volatility (vega); a loss on a fast-moving day points to gamma; a small, steady gain on a calm day is usually theta at work.

If you are new to reading a strategy's results, start with how to read a strategy's daily P&L ledger, then browse the strategies on the overview page.