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Option premium

Also written Premium · Option price

The price an option buyer pays the seller for the right the contract carries — non-refundable, and made up of intrinsic value plus time value.

In plain language

An option gives its buyer a right and no obligation; the seller takes on an obligation and no right. That asymmetry has to be paid for, and the payment is the premium.

It changes hands up front and it is non-refundable. Whatever happens afterwards, the buyer's maximum loss is the premium, and the seller's maximum gain is the premium.

Nobody sets it. The workbook is blunt on this point: premiums are not fixed by the exchange or by SEBI — they are discovered by buyers and sellers, exactly as futures prices are.

How it works

Premium splits into two parts, and only one of them can be computed from today's prices:

Premium = Intrinsic value + Time value

Intrinsic value is the amount by which the option is in the money: S - X for a call and X - S for a put, floored at zero. It is never negative, so at-the-money and out-of-the-money options have none.

Time value is the rest. It exists because the option has not expired yet, and it decays to zero by expiry — non-linearly, accelerating as expiry approaches. This is why options are called wasting assets, and why the workbook notes that option sellers hold a fundamental advantage: one of the two components is inherently biased downwards.

Five variables drive the premium:

Factor risesCall premiumPut premium
Price of the underlyingRisesFalls
Strike priceFallsRises
Time to expiryRisesRises
VolatilityRisesRises
Interest rateRisesFalls

The formula

Premium = Intrinsic value + Time value

Intrinsic value of a call = max(Spot - Strike, 0)
Intrinsic value of a put  = max(Strike - Spot, 0)
Time value                = Premium - Intrinsic value

A worked example

The workbook's zinc option. Strike Rs 180, call premium Rs 10, put premium Rs 8, one month to expiry.

At expiry, per unit:

Market priceCall buyerCall sellerPut buyerPut seller
220+Rs 30−Rs 30−Rs 8+Rs 8
200+Rs 10−Rs 10−Rs 8+Rs 8
160−Rs 10+Rs 10+Rs 12−Rs 12
140−Rs 10+Rs 10+Rs 32−Rs 32

Read the call column downwards. Below Rs 180 the call buyer's loss stops at Rs 10 however far the market falls — the premium, and nothing more. The call seller's gain stops at the same Rs 10 however far it falls.

Now split a live premium, using the workbook's own example. A commodity future is at Rs 1,280, and a call on it quotes a premium of Rs 200 against a strike of Rs 1,170:

Intrinsic value = 1,280 - 1,170 = Rs 110
Time value      = 200 - 110     = Rs  90

Rs 90 of that Rs 200 is being paid purely for time remaining, and it is gone by expiry even if the future never moves.

Why NISM asks about it

Chapter 4 (Commodity Options), section 4.2 for the terminology and section 4.4 for the determinants — the factor table above is reproduced almost verbatim in the workbook and is examined directly. Expect "split this premium into intrinsic and time value" arithmetic, a question on which way a rise in interest rates moves a put premium (down), and the payoff table logic that the buyer's loss is capped at the premium.

Common exam traps

  • The premium is not the strike price. The strike is the price at which the commodity changes hands; the premium is what the right to that strike costs.
  • Intrinsic value can never be negative. An out-of-the-money option has zero intrinsic value and its entire premium is time value.
  • Time to expiry raises both call and put premiums, unlike the underlying price, which moves them in opposite directions.
  • Time decay is not linear — it accelerates towards expiry, so a one-month option is worth considerably more than half a two-month option.
  • The premium is non-refundable. Letting an option lapse unexercised does not return it.
  • Rising interest rates lift calls and depress puts. Volatility, by contrast, lifts both.

Check yourself

  1. 1.A commodity call option has a strike price of Rs 1,000, the current market price of the underlying commodity futures is Rs 1,150, and the option premium is Rs 200. What is its time value?

    1. a)Rs 150
    2. b)Rs 100
    3. c)Rs 50
    4. d)Rs 200
    Show the answer

    Answer: (c) Rs 50

    (This is a sample question from the NISM workbook.)

    Premium = Intrinsic Value + Time Value

    • Intrinsic value of a call = S − X = 1,150 − 1,000 = Rs 150
    • ⚠️ Time value = Premium − Intrinsic value = 200 − 150 = Rs 50

    Option (a) Rs 150 is the intrinsic value offered as if it were the answer, and option (d) Rs 200 is the whole premium — so read carefully which of the three quantities the question wants.

    The rules that constrain these two components:

    • Only in-the-money options have intrinsic value; at-the-money and out-of-the-money options have zero intrinsic value
    • The intrinsic value of an option cannot be negative — because no one would like to exercise his right under a no-advantage condition
    • ATM and OTM options will have only time value

    And the deeper split worth remembering: of the five pricing determinants, underlying price and strike price create intrinsic value, while volatility, time to expiry and interest rate create time value.

  2. 2.Assuming all other factors remain constant, which statement is TRUE regarding the relation between interest rates and option premium?

    1. a)Higher interest rates will decrease the value of both call and put options
    2. b)Higher interest rates will increase the value of both call and put options
    3. c)Higher interest rates will increase the value of a call option and decrease the value of a put option
    4. d)Higher interest rates will decrease the value of a call option and increase the value of a put option
    Show the answer

    Answer: (c) Higher interest rates will increase the value of a call option and decrease the value of a put option

    (This is a sample question from the NISM workbook.)

    "High interest rates will increase the value of a call option and a decrease in the value of a put option."

    This sensitivity is measured by Rho — the change in option price given a one percentage point change in the risk-free interest rate. An increase in interest rate increases the call option price but reduces the put option price. Similarly, a reduction in interest rate increases the put option price but reduces the call option price.

    This is the row of the determinants table most often guessed wrong, so it is worth having a reason rather than a memory. A call buyer has locked in a purchase price he will pay later — the higher the interest rate, the more that deferral is worth. A put buyer has locked in a sale price he will receive later — the higher the rate, the more that delay costs him.

    The full table:

    Factor risesCallPut
    Price of underlyingRisesFalls
    Strike priceFallsRises
    Time to expiryRisesRises
    VolatilityRisesRises
    Interest rateRisesFalls

    Only volatility and time move both premiums the same way — which is what makes options (a) and (b) tempting.

  3. 3.Silver futures at Rs 60,000 with the Rs 60,000-strike call at Rs 3,500; at Rs 63,000 the premium is Rs 6,100 and at Rs 66,000 it is Rs 8,800. What are Delta at these two moves and Gamma between them?

    1. a)Delta 0.867 and 0.90; Gamma 0.00001
    2. b)Delta 0.90 and 0.867; Gamma 0.001
    3. c)Delta 2,600 and 2,700; Gamma 0.033
    4. d)Delta 0.05 and 0.10; Gamma 0.00001
    Show the answer

    Answer: (a) Delta 0.867 and 0.90; Gamma 0.00001

    • At Rs 63,000: (6,100 − 3,500) / 3,000 = 2600/3000 = ⚠️ 0.867
    • At Rs 66,000: (8,800 − 6,100) / 3,000 = 2700/3000 = ⚠️ 0.90

    ⚠️ Gamma = (0.867 − 0.900) / (−3000) = 0.00001, i.e. 0.001%

    Read what the two deltas are telling you. As the call moved deeper into the money, delta rose from 0.867 towards 1 — the option began behaving more and more like the underlying itself. Gamma is the speed of that transition: it "signifies the speed with which an option will go either in-the-money or out-of-the-money due to a change in price of the underlying asset." It is "the second derivative option with regard to price of the underlying asset."

    Option (c) is the trap for anyone who forgets to divide — Rs 2,600 and Rs 2,700 are the raw premium changes, not deltas. Option (b) reverses the order, which matters because delta rises as a call goes deeper ITM.

    Delta signs to carry into the exam: call buyer POSITIVE (like a long or bull position), call seller NEGATIVE, put buyer NEGATIVE (like a short or bear position), put seller POSITIVE — the seller's figure always the same magnitude with the opposite sign.

Where this is taught

Free preparation for NISM Series XXI-B

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