Chapter 4: Introduction to Options
NISM Series VIII — Equity Derivatives | 20% weightage | ~20 exam questions
What this chapter is about
Options are the most important chapter in this exam — 20% weightage, 71 questions in the question bank, and the highest trap rate of any chapter. If you master this one chapter alone, you're more than a third of the way to passing.
The core idea is simple: an option gives you the right but not the obligation to buy or sell something at a fixed price. You pay a premium for that right. The seller receives the premium and takes on the obligation. Everything else in this chapter flows from that one sentence.
Key concepts
Call Option — right to BUY the underlying at the strike price on or before expiry. Buyer is bullish. Seller is bearish or neutral.
Put Option — right to SELL the underlying at the strike price on or before expiry. Buyer is bearish. Seller is bullish or neutral.
Strike Price (Exercise Price) — the fixed price at which you can buy (call) or sell (put). NOT the market price. This is the most common trap in the exam.
Option Premium — what the buyer pays to the seller for the right. Made up of two parts:
- Intrinsic Value = amount the option is in-the-money (minimum zero, never negative)
- Time Value = everything else (uncertainty, time remaining, volatility)
Moneyness — where the option sits relative to the market:
- ITM (In the Money) → profitable to exercise right now
- ATM (At the Money) → strike = spot price
- OTM (Out of the Money) → not profitable to exercise, intrinsic value = zero
European vs American Options — In India, ALL index options (Nifty, Bank Nifty) are European — exercise only on expiry day. Stock options are physically settled. This comes up frequently.
Expiry — Last Thursday of the month (or day before if Thursday is a holiday). Update: NSE shifted to Tuesday from September 2025.
The 5 Greeks — this is where the exam fights you
Think of Greeks as sensitivity meters. Each one measures how much the option premium moves when one specific thing changes.
| Greek | Measures sensitivity to | Direction for Calls |
|---|---|---|
| Delta | Change in underlying price | 0 to +1 |
| Gamma | Rate of change of Delta | Always positive |
| Theta | Passage of time (time decay) | Negative (premium falls) |
| Vega | Change in volatility | Positive |
| Rho | Change in interest rates | Positive for calls |
Delta deep dive — the most tested Greek:
- Deep ITM call → Delta near 1 (moves almost like the stock)
- ATM call → Delta near 0.5
- Deep OTM call → Delta near 0 (barely moves)
- Put Delta ranges from 0 to -1 (opposite direction)
Vega — higher volatility = higher premium for BOTH calls and puts. Makes sense — more volatility = more chance of a big move = option worth more.
Theta — the silent killer. Every day that passes, the time value portion of the premium decays. This decay accelerates as expiry approaches. Theta hurts option buyers, benefits option sellers.
Rho — interest rate goes up → call premium goes up, put premium goes down. Think of it as cost of carry.
Real market example — Nifty options
It's expiry week. Nifty is at 24,500. You buy a 24,500 CE (Call option, ATM) for ₹150 premium. Lot size = 75.
Your cost: ₹150 × 75 = ₹11,250
If Nifty rises to 24,800 by expiry:
- Intrinsic value = 24,800 - 24,500 = ₹300
- You receive ₹300 × 75 = ₹22,500
- Profit = ₹22,500 - ₹11,250 = ₹11,250
If Nifty stays at 24,500 or falls:
- Option expires worthless (OTM or ATM at expiry = zero intrinsic value)
- You lose the full premium: ₹11,250
- Maximum loss for buyer = premium paid (always)
- Maximum gain for buyer = unlimited (theoretically)
For the seller of that same call:
- Maximum gain = ₹11,250 (the premium received)
- Maximum loss = unlimited (if Nifty rockets to 30,000, seller bleeds)
This is the asymmetry of options — buyer has limited risk, unlimited upside. Seller has limited gain, unlimited risk.
Payoff summary — memorise this table
| Position | Max Profit | Max Loss | View |
|---|---|---|---|
| Buy Call | Unlimited | Premium paid | Bullish |
| Sell Call | Premium received | Unlimited | Bearish/Neutral |
| Buy Put | Strike - Premium | Premium paid | Bearish |
| Sell Put | Premium received | Strike - Premium | Bullish/Neutral |
Trap Alert — the 5 questions students consistently get wrong
Trap 1: "A call option gives the buyer the right to buy at MARKET price" → FALSE The right is to buy at the STRIKE price, not market price. The whole point of an option is locking in a price. If it was market price, why would you need the option?
Trap 2: "Vega measures change in delta" → FALSE. That's Gamma. Memory hook: Vega = Volatility. Gamma = Gradient of delta (rate of change).
Trap 3: "Theta measures sensitivity to volatility" → FALSE. That's Vega. Memory hook: Theta = Time. Vega = Volatility. Never mix these two.
Trap 4: "Delta is the change in option price for a 1% change in interest rates" → FALSE. That's Rho. Delta = price sensitivity. Rho = rate sensitivity.
Trap 5: "A long put can be closed by shorting a call with same strike and expiry" → FALSE. You close a long put by SELLING the same put (same strike, same expiry). You can only close an option position with the SAME type of option — put with put, call with call.
Must-remember numbers and rules
- Delta range: Calls = 0 to +1 | Puts = 0 to -1
- Far OTM option → Delta near 0
- Deep ITM option → Delta near +1 (call) or -1 (put)
- ATM option → Delta near 0.5 (call) or -0.5 (put)
- Intrinsic value = never negative (minimum is zero)
- Time value = zero at expiry (only intrinsic value remains)
- Higher volatility = higher premium (both calls and puts)
- Higher interest rates = higher call premium, lower put premium
- Option buyers pay premium → margin not required
- Option sellers receive premium → initial margin required (unlimited risk)
- In India, index options = European style (exercise only at expiry)
- Option lot quantity = only the specified lot size, not more or less
Weightage note
20% of the exam = ~20 questions. CH4 has 71 questions in the bank — highest of any chapter. The exam will heavily test:
- Greeks (especially confusing Vega/Theta, Delta/Rho) — expect 6-8 questions
- Payoff scenarios (who profits when price rises/falls) — expect 4-5 questions
- Moneyness and intrinsic/time value — expect 3-4 questions
- European vs American, closing positions — expect 2-3 questions
Priority order: Greeks → Payoffs → Moneyness → Contract specs → Pricing factors
Master CH4 and you've secured 20 marks before walking in.
Quick revision — 60 second scan before exam
- Call = right to BUY at strike | Put = right to SELL at strike
- Buyer pays premium, has right | Seller receives premium, has obligation
- ITM = profitable | ATM = strike equals spot | OTM = intrinsic value zero
- Premium = Intrinsic Value + Time Value
- Delta (price) | Gamma (delta's rate) | Theta (time) | Vega (volatility) | Rho (rates)
- Buyer max loss = premium | Seller max loss = unlimited (call) / strike price (put)
- Close positions with SAME option type, same strike, same expiry
- All index options in India = European style