How to Pick the
Right Strike Price
Strike selection is the decision that most determines your risk-reward in any options trade — yet most retail traders pick strikes by feel rather than a framework.
A wrong directional view can sometimes be salvaged. A wrong strike almost never can. The strike you choose determines how much you pay, how sensitive the position is to the underlying's move, how quickly time erodes value, and where your break-even sits. This guide gives you a systematic way to choose strikes on NSE indices — anchored in the greeks, open interest, and the specific trade objective.
The three moneyness buckets
Every strike falls into one of three categories relative to the current underlying price:
- In-the-money (ITM) — for a call, the strike is below the spot price; for a put, it is above. ITM options have high intrinsic value, move nearly 1:1 with the underlying at deep ITM levels, cost more, but decay more slowly.
- At-the-money (ATM) — strike is closest to the current spot. Delta near 0.50, highest time value component, most sensitive to short-term moves.
- Out-of-the-money (OTM) — for a call, the strike is above spot; for a put, it is below. Lower cost, lower delta, highest percentage sensitivity to IV, decays fastest, lowest probability of expiring with value.
The right bucket depends entirely on what you are trying to do.
Matching the strike to the trade objective
Directional trade, high conviction, limited time horizon: ATM or one strike OTM. You pay a reasonable premium, get meaningful delta (0.40–0.55), and do not need a monster move to make money. The break-even is close to the current price.
Speculative bet on a large move: Two to three strikes OTM. The premium is small relative to the potential payout if the move materialises, but the probability of profit is low. Size conservatively and treat it as a defined-risk lottery ticket rather than a core trade.
Hedging an existing equity portfolio: ITM or ATM puts. The higher delta means the hedge responds quickly to a decline. Cheap OTM puts are tempting but provide inadequate protection on moderate drawdowns where the real damage happens.
Short premium (selling options): One to two strikes OTM so there is a buffer between the market and your short strike while still collecting meaningful premium.
A worked example with NIFTY
Suppose NIFTY is near 22,500 on a Tuesday with three days to weekly expiry. You expect a 150-point rally to 22,650 over the next two sessions. The available call strikes are:
- 22,400 CE (100 points ITM) — trading at 175, delta 0.68
- 22,500 CE (ATM) — trading at 95, delta 0.50
- 22,600 CE (100 points OTM) — trading at 40, delta 0.28
- 22,700 CE (200 points OTM) — trading at 15, delta 0.12
At the NIFTY lot size of 75, a 150-point rally to 22,650 would produce the following approximate gains (ignoring IV change and theta):
- 22,400 CE: delta gain roughly 150 × 0.68 = 102 points × 75 = Rs 7,650 per lot. Cost Rs 13,125.
- 22,500 CE (ATM): 150 × 0.50 = 75 points × 75 = Rs 5,625 per lot. Cost Rs 7,125. Return on capital: 79%.
- 22,600 CE: 150 × 0.28 = 42 points × 75 = Rs 3,150 per lot. Cost Rs 3,000. Return on capital: 105% — but only if the move reaches 22,650; below 22,600, the option expires worthless.
- 22,700 CE: lottery-style. Even with the full 150-point move, the option stays 50 points OTM at expiry and likely expires worthless.
The 22,600 CE looks attractive on percentage return, but the probability condition is stricter — NIFTY must exceed 22,640 to cover cost. A trade that is right on direction but undershoots by 30 points still loses everything. The ATM strike offers a better risk-reward for moderate conviction.
How open interest informs strike selection
Before committing to a strike, check the NIFTY option chain for OI concentration. The strike with the highest call OI is where writers have planted the heaviest resistance. The strike with the highest put OI is where support is defended. Buying a call at the resistance strike is picking a fight against a large number of sellers defending that level. It is wiser to choose a strike just below the resistance wall or wait for a confirmed breakout above it.
Similarly, max pain — the level where total option value is minimised at expiry — gives you a gravitational centre. Strikes close to max pain tend to attract the market on expiry day; strikes far away from max pain carry a headwind.
Time to expiry changes the equation
With more than a week to expiry, OTM options have time to come into the money and the theta cost per day is manageable. Close to expiry, OTM options are nearly all time value — they decay rapidly and require the move to happen immediately. As expiry approaches, bias toward ATM for buying and further OTM for selling to give your short strikes more buffer against last-hour volatility.
Implied volatility and the strike decision
When IV is elevated (typically before events like RBI MPC or earnings), premiums at every strike are inflated. Buying in a high-IV environment means you are also making a bet that volatility stays high. If IV contracts post-event, your option can lose value even if the direction is right. In high-IV environments, prefer defined-risk spreads (buy one strike, sell another OTM) to cap the vega exposure. Track IV levels on the implied volatility dashboard.
Frequently asked questions
Should I buy ATM or OTM options on NIFTY?
ATM options offer the best balance of delta sensitivity and cost for most directional trades. OTM options are cheaper but require a larger move and have a lower probability of profit. Unless you have a strong conviction on a large move within a short time frame, ATM or one strike OTM is generally the better starting point for buyers.
How does open interest help me pick a strike?
High put OI at a strike signals that writers are defending it as support. High call OI signals resistance. The strikes with the heaviest OI concentration set the practical range the market is expected to stay within. Entering a directional trade beyond those walls requires the market to break a line that a large number of writers are defending.
What is the role of delta in strike selection?
Delta tells you how much the option price moves per one-point move in the underlying. An ATM option has a delta of approximately 0.50. A 0.30 delta OTM option moves only 30 paise for every rupee the underlying moves, so it needs a bigger directional move just to break even against time decay.
See the full chain with OI, IV, and greeks
TradePulse shows live delta, OI concentration, and max pain for every NSE index and stock option — the data you need before you pick a strike.