Strategy Greeks

Bull Spread: Greek Profile

A bull call spread — long a lower call, short a higher call — is net positive Delta with small and shifting Gamma, Theta and Vega, a defined-risk bullish trade whose secondary Greeks are largely neutralised by the short leg.

Quick answer: A bull call spread — long a lower call, short a higher call — is net positive Delta with small and shifting Gamma, Theta and Vega, a defined-risk bullish trade whose secondary Greeks are largely neutralised by the short leg.

Simple explanation

You buy a call and sell a higher-strike call against it, so you are bullish but with capped profit and capped loss. The short leg pays for part of the long leg, and it also cancels out most of the Vega and much of the Theta and Gamma you would carry from a plain long call. The result is a cleaner directional bet: your net Delta is positive but modest, and the position is far less sensitive to volatility and time than a naked long call.

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Bull Spread: Greek Profile

Loss is capped at the net debit below the lower strike; profit is capped at the strike difference minus the debit above the upper strike at expiry.

Detailed explanation

Delta: positive but capped

The long lower call has more Delta than the short higher call, so net Delta is positive — you are bullish. With Nifty at 24,500, long the 24,500 call (Delta 0.52) and short the 24,800 call (Delta 0.35) gives net Delta about +0.17 per unit. That net Delta is highest when Nifty sits between the strikes and fades toward zero once price moves well above the upper strike, because both legs approach Delta 1 and offset — this is what caps the profit.

Gamma: nearly netted out

The long call is long Gamma and the short call is short Gamma, so the net Gamma is small. Between the strikes net Gamma is mildly positive; above the short strike it turns mildly negative. Compared with a naked long call, the spread has far less curvature — you give up the explosive upside acceleration in exchange for a cheaper, defined-risk position.

Theta: much reduced

A naked long call bleeds full Theta; the short call in a bull spread collects Theta, offsetting most of it. Net Theta is small and its sign depends on where Nifty is relative to the strikes — mildly negative when the spread is OTM and can turn slightly positive when Nifty is above the short strike and the position is deep ITM. This is why a bull spread survives a quiet week far better than a long call.

Vega: largely neutralised

This is the biggest advantage. The long call's positive Vega and the short call's negative Vega roughly cancel, so net Vega is small. A bull spread is therefore much less exposed to IV crush — you can put one on before an event without the volatility risk of a naked long call. If anything the spread is slightly long Vega when OTM and slightly short Vega when ITM.

Net Greeks of the bull call spread

Greek	Position	What it means
Delta	Net positive, modest	Bullish exposure, strongest between the strikes, fading to zero above the upper strike.
Gamma	Small (near netted)	Mildly positive between strikes, mildly negative above — far less curvature than a naked call.
Theta	Small	The short call offsets most decay; slightly negative when OTM, can turn positive when deep ITM.
Vega	Small (near netted)	Legs cancel most volatility exposure, so IV crush barely affects the spread.

Practical example (Nifty)

Illustrative — Nifty spot 24500, lot size 75

Nifty at 24,500. Buy the 24,500 CE at ₹180 and sell the 24,800 CE at ₹80, net debit ₹100 x 75 = ₹7,500 — this is also your maximum loss. Maximum profit is the strike gap minus debit: (300 − 100) x 75 = ₹15,000, reached if Nifty closes at or above 24,800 at expiry. Net Delta about +0.17, net Vega near zero. If Nifty rises 150 points to 24,650, the spread gains roughly its net Delta times the move — around ₹0.17 x 150 x 75 = ₹1,900 — with almost no Vega distortion even if IV moved, unlike a naked long call that would swing with volatility.

Why it matters in practice

A defined-risk bullish trade: both maximum profit and maximum loss are known at entry.
The short leg neutralises most Vega, so a bull spread is a good way to be bullish into an event without IV-crush risk.
Net Theta is small, so the position survives a flat week far better than a naked long call.
Profit is capped — you trade the long call's unlimited upside and Gamma for lower cost and lower risk.

Common mistakes

Setting the strikes too close together, capping profit so tightly that the trade barely pays even when right.
Expecting a bull spread to explode like a naked long call — its netted Gamma and Vega deliberately dampen big-move upside.
Ignoring that net Delta fades above the upper strike, so holding for more gains after Nifty passes it earns nothing extra.
Choosing very wide strikes that raise cost and loss toward that of an outright long, defeating the point of spreading.

Professional usage

Professionals use bull spreads to express a measured bullish view with a defined budget, choosing the width to match their target — a narrow spread for a small expected move, a wider one for a bigger move at higher cost. Because net Vega is small, they happily deploy spreads ahead of results or Budget where a naked long call would be crushed. They place the short strike near their price target so maximum profit lines up with the expected move, and they close early once most of the spread's value is captured rather than waiting for the last few rupees against decay.

Key takeaway

A bull call spread is a bullish Delta trade with its Gamma, Theta and Vega deliberately muted by the short leg — you accept capped profit in return for lower cost, defined risk and near-immunity to IV crush.

Frequently asked questions

What is the Greek profile of a bull call spread?

Net positive Delta with small net Gamma, small net Theta and small net Vega. The short leg neutralises most of the secondary Greeks, leaving a clean, defined-risk bullish bet.

Why does a bull spread have low Vega?

The long call's positive Vega and the short call's negative Vega largely cancel, so the spread is far less exposed to changes in implied volatility than a naked long call.

Is a bull spread better than buying a call before an event?

Often, yes. Because its net Vega is small, a bull spread avoids the IV crush that can sink a naked long call even when the direction is right.

What is the maximum profit and loss on a bull call spread?

Maximum loss is the net debit paid; maximum profit is the difference between strikes minus that debit. Both are fixed at entry, making it a defined-risk trade.

Why is my bull spread not gaining even though Nifty rose?

Its net Delta is modest and fades above the upper strike. Once Nifty passes the short strike, both legs offset and the spread stops gaining — the profit is capped.

How wide should I make a bull spread?

Match the width to your expected move and budget: narrow spreads are cheaper with smaller capped profit, wider spreads cost more and risk more but allow larger profit. Place the short strike near your target.

Does a bull spread suffer from time decay?

Much less than a naked long call. The short call collects Theta that offsets most of the long call's decay, so net Theta is small and the position survives quiet periods far better.

Sources & references

Last reviewed 7 July 2026. Educational content only — not investment advice.