Introductory Context
"The strike price determines how much the underlying must move for your option to profit, how sensitive your option is to underlying moves (delta), and the probability that it expires in the money. Strike selection is the most consequential decision in options trading after determining direction. "
The Strike Price Spectrum — Deep ITM to Deep OTM
When Nifty is trading at 24,150, the option chain offers strikes from perhaps 21,000 to 27,000. Not all are relevant to every trader. Understanding the spectrum from deep ITM to deep OTM — and the risk-reward profile at each point — is what makes strike selection a skill rather than a guess.
Deep ITM — High Cost, High Delta, Low Leverage
A deep ITM call — say the 22,500 CE with Nifty at 24,150 — has intrinsic value of ₹1,650. Its premium will be approximately ₹1,650 plus small time value. Its delta will be close to 0.90–1.00, moving almost tick-for-tick with Nifty. In effect, a deep ITM call behaves almost like a futures contract — high cost, high sensitivity, low leverage effect. Rarely the right choice for retail directional trades because it provides little leverage advantage over futures.
ATM — The Sweet Spot for Most Retail Trades
The at-the-money strike — closest to the current spot — is where the most trading volume concentrates. ATM options have delta of approximately 0.45–0.55, respond meaningfully to Nifty moves, have the highest time value (and therefore highest absolute theta), and the most liquidity — tightest bid-ask spreads, highest volumes, fastest fills. For most directional trades expressing a moderate view, ATM or slightly OTM is the appropriate choice.
OTM — Low Cost, Low Probability, High Leverage on Success
OTM options are cheaper because they require the underlying to move further before becoming profitable. A 24,700 CE with Nifty at 24,150 requires a 550-point move just to reach the strike — and break-even is strike plus premium, so perhaps 650–700 points needed for profitability. OTM options are appropriate for specific situations: large expected moves around events, as the sold leg in spread structures, or as cheap portfolio insurance. Buying far OTM options routinely as directional trades is a statistically losing approach.
The Far OTM Lottery Ticket Trap
The most common strike selection mistake: buying cheap far-OTM options because 'if Nifty moves just a bit, I could make 10x.' A ₹10 premium OTM option with delta 0.08 has approximately 8% probability of expiring ITM. It expires worthless approximately 92% of the time. The ₹10 feels cheap until you buy 10 lots every week and lose ₹5,625 per week on average. The 'cheap' label masks the low probability of success.
Delta as Your Strike Selection Guide
The most practical framework for choosing a strike is delta. Delta tells you approximately how much your option's value will change per ₹1 move in the underlying — and roughly approximates the probability of expiring ITM.
• deep ITM — high cost, moves like the underlying, low leverage: Delta 0.70–0.90.
• ATM — balanced cost and leverage, most liquid, best for moderate directional views: Delta 0.45–0.60.
• slightly OTM — lower cost, requires a moderate move, good for moderate directional conviction: Delta 0.25–0.40.
• OTM — low cost, requires significant move, appropriate for event-driven large-move expectations: Delta 0.10–0.20.
• far OTM — very low cost, very low probability, primarily useful in spread structures: Delta below 0.10.
For most retail directional trades, a delta of 0.30–0.50 is the recommended starting range. This places you at or slightly OTM, gives meaningful exposure to the anticipated move, and avoids paying for intrinsic value you do not need or buying a contract with very low probability of success.
The 0.35 Delta Rule of Thumb
If unsure which strike to pick, start with the strike having delta approximately 0.35 — typically 1–2 strikes OTM from ATM for Nifty options. At this delta, your option moves ₹0.35 for every ₹1 Nifty moves. A 200-point Nifty move generates approximately ₹70 per unit in option value gain, on a premium that might be ₹80–100. Good risk-reward if your directional thesis is correct.
Adjusting for IV Environment
When India VIX is high — above 18 — options premiums are inflated. An ATM option costing ₹80 in a VIX-14 environment might cost ₹160 in a VIX-22 environment. In high-IV environments, buying ATM means your break-even requires a larger move (more premium to recover). Consider moving one strike closer to ITM — the slightly higher premium is offset by better delta and lower break-even distance. Or use a spread structure to reduce net premium outlay. VIX below 13: standard ATM selection is fine — premiums are relatively cheap.
Strike Selection in the myfinversity Series
Book 4 of the myfinversity Options Trading Series — The Greeks: Delta, Gamma, Theta, Vega and Rho — dedicates a full chapter to delta-based strike selection, with worked examples across different market environments and IV conditions. For the complete quantitative treatment of this subject, Book 4 is the reference.