Butterfly Spread on Nifty — Expiry Day Strategy

The butterfly spread is the cheapest defined-risk strategy in options trading. When I expect Nifty to settle near a specific level at expiry — and I want to bet on this view with minimum capital at risk — the butterfly is my go-to. I have used it extensively on Nifty weekly expiry days (Thursdays) and the risk-to-reward profile is extraordinary: risk ₹500-1,500 per lot to make ₹3,000-6,000 per lot. No other options strategy offers a potential 3:1 to 5:1 payoff with such low absolute cost.

The butterfly spread is particularly powerful on Nifty expiry days when you have a view on where the index will close. This guide covers the mechanics, the math, the optimal setups, and how I use butterflies as an expiry-day income strategy.

Butterfly Spread Mechanics — How It Works

A butterfly spread uses three strike prices with the same expiry. The standard long call butterfly involves:

1. Buy 1 lot of a lower-strike call (ITM)
2. Sell 2 lots of a middle-strike call (ATM — your target level)
3. Buy 1 lot of a higher-strike call (OTM)

The middle strike is where you expect Nifty to close at expiry. Maximum profit occurs if Nifty closes exactly at the middle strike. The trade costs very little because the two sold calls nearly pay for the two bought calls.

Here is a concrete example with Nifty at 24,000, targeting a close at 24,000:

Leg	Strike	Action	Lots	Premium	Total (25 shares/lot)
Lower Wing	23,800 CE	Buy	1	₹248	-₹6,200
Body (Target)	24,000 CE	Sell	2	₹165	+₹8,250
Upper Wing	24,200 CE	Buy	1	₹98	-₹2,450
Net Cost (Max Loss)					-₹400

Net cost: ₹400 per butterfly. This is your maximum loss if Nifty closes below 23,800 or above 24,200.

Maximum profit: Width of one wing (200 points) minus net cost (16 points) = 184 points × 25 = ₹4,600 per butterfly. This occurs if Nifty closes exactly at 24,000.

Risk-to-reward: ₹400 risk for ₹4,600 potential reward = 1:11.5 ratio. This is why butterfly spreads are so compelling.

The Payoff Profile — Understanding Your Profit Zone

Nifty at Expiry	Butterfly P&L	Return on ₹400 Cost	Comment
23,700 or below	-₹400	-100%	Max loss (all calls expire worthless or net out)
23,816	₹0	0%	Lower breakeven
23,900	+₹2,100	+525%	Approaching sweet spot
24,000	+₹4,600	+1,050%	Max profit — center strike
24,100	+₹2,100	+525%	Still very profitable
24,184	₹0	0%	Upper breakeven
24,300 or above	-₹400	-100%	Max loss

The profit zone spans from 23,816 to 24,184 — a 368-point range (about 1.5% of Nifty). Any close within this range is profitable, with maximum profit at the center. The butterfly is profitable as long as your target is roughly correct — you do not need to nail the exact close.

Expiry Day Butterfly — My Favorite Setup

Butterfly spreads become most valuable on expiry day (Thursday for Nifty weekly options) because of a phenomenon called "gamma explosion." On expiry day, ATM options have extremely high gamma, meaning their value changes rapidly with small moves. But the butterfly's structure neutralizes this gamma, leaving you with pure convergence profit as the index approaches your target.

My expiry day process:

Step 1 — Identify the magnet level (9:15-10:00 AM IST): On Thursday morning, I look at the option chain for the current weekly expiry. The strike with the highest open interest (OI) on the put side is typically the "max pain" level — where Nifty tends to gravitate on expiry day. This is my butterfly target.

Step 2 — Set up the butterfly (10:00-11:00 AM IST): I place the butterfly centered on the max pain level with 200-point wings. I use limit orders on each leg, typically getting filled within ₹2-3 of my target price.

Step 3 — Wait for convergence (11:00 AM - 3:30 PM IST): As expiry approaches, Nifty tends to drift toward the max pain level. If it stays within my profit zone, the butterfly's value increases rapidly in the last 2 hours. I exit at 3:00 PM IST rather than holding to 3:30 PM, avoiding the final-minute volatility.

Trade Parameter	My Standard Setup	Alternative (Wider)
Wing Width	200 points	300 points
Typical Cost	₹300-600/butterfly	₹500-900/butterfly
Max Profit	₹4,400-4,700	₹6,600-7,000
Profit Zone Width	~370 points (1.5%)	~570 points (2.4%)
Win Rate (Historical)	35-40%	45-50%
Avg Profit When Win	₹2,500-3,500	₹3,000-4,500

The win rate of 35-40% might seem low, but the risk-reward math makes it highly profitable. Even winning only 35% of the time, the average winning butterfly pays 6-8x the cost, resulting in a positive expected value over 20+ trades.

Iron Butterfly — The Enhanced Version

An iron butterfly is a variation that uses both calls and puts, centering around the ATM strike. It is structurally similar to the iron condor but with the short strikes at the same level (ATM) instead of spread apart.

Setup with Nifty at 24,000: Sell 1 lot 24,000 CE + Sell 1 lot 24,000 PE (ATM straddle) and Buy 1 lot 24,200 CE + Buy 1 lot 23,800 PE (wing protection).

The iron butterfly collects more premium upfront (because you are selling ATM options) but has a narrower profit zone than a regular butterfly. I use iron butterflies when I have very high conviction that Nifty will close near a specific level — typically on low-VIX expiry days when the index barely moves.

When NOT to Trade Butterflies

High VIX days (above 18): When volatility is elevated, Nifty can swing 300+ points on expiry day, easily blowing through your butterfly's profit zone. I skip butterflies entirely during high-VIX environments and switch to straddles or iron condors instead.

Event days: Butterflies on RBI policy Thursdays, Budget week, or US Fed decision days are gambling, not trading. The directional moves on these days overwhelm the butterfly structure.

Trending markets: When Nifty has trended strongly (3%+ in one direction over 3 days), the butterfly's assumption of mean reversion to a specific level breaks down. Trends tend to continue, pushing the index past your butterfly's wings.

Position Sizing for Butterflies

Because butterflies have such low cost and high potential reward, position sizing discipline is critical. My rules:

Maximum butterflies per expiry: 3. I might set up butterflies at three different target levels if I am uncertain about the exact close (for example, at 23,900, 24,000, and 24,100). Total risk: ₹1,200-1,800 for a potential ₹13,800 combined profit if one hits.

Maximum weekly allocation: 1% of total trading capital. With a ₹10 lakh account, I spend a maximum of ₹10,000 per week on butterflies. This ensures that a string of losing weeks (which happens — I have had 5 consecutive losing butterfly weeks) does not meaningfully impact my capital.

Profit target: I exit when the butterfly reaches 60% of its maximum value. Chasing the last 40% exposes me to late-day reversal risk. A ₹400-cost butterfly that reaches ₹3,000 in value gets closed — I do not wait for it to reach ₹4,600.

The butterfly pairs well with other strategies in my toolkit. On weeks where I run an iron condor, I sometimes add a butterfly at my target level for additional profit if Nifty pins at that level. The option Greeks guide explains the gamma dynamics that make butterflies work on expiry day. For broader strategy context, see my Nifty 50 strategies. Practice butterfly timing on Exness demo accounts before going live on NSE.