Chapter 02 of 6 · 7 lessons · Concept, Case, Tool
The Greeks
The Greeks describe how an option price responds to the things around it. Every lesson here pairs the definition with a control you can move, so the response is something you watch rather than something you are told.
An option premium responds to four things at once: where the index is, how fast it is moving, how much time remains, and what the market is charging for uncertainty. The Greeks are the four figures that separate those responses so each can be read on its own.
Each one holds the others still. Delta says what a one-point move in the index is worth; theta says what a day costs; vega says what a percentage point of implied volatility is worth; gamma says how quickly delta itself changes. Read individually each looks like a prediction and each will look wrong. Read together they decompose a real price move almost exactly.
That is this chapter's argument, and it is demonstrated rather than asserted. On 23 September 2026 a NIFTY call carrying a delta of 0.542 gained 18.30 rupees on an 89-point rise, where delta alone pointed at 48.32. The four Greeks account for 14.80 of that difference; what remains is the residual any first-order approximation leaves behind.
By the end of this chapter
- Read a delta figure and know what it does and does not predict
- Explain why an option can lose money on a day the index moves in its favour
- Take a real price move apart and attribute it to each Greek in turn
- Price any contract yourself at your own level, volatility and days remaining
The lessons
In order, though each one stands on its own.
Common questions
Which Greek matters most?
Whichever one moved. On 23 September 2026 delta pointed at plus 48.32 rupees and vega at minus 34.80 on the same contract in the same session, so the answer that day was volatility.
Do I need Black-Scholes to use the Greeks?
Not to read them, but something has to produce them. The Greeks describe behaviour before expiry, which requires a model. Every figure in this chapter is solved with Black-Scholes and labelled as a model output, never placed beside traded prices without saying which is which.
Why do implied volatility readings go strange near expiry?
Solving for volatility means dividing by vega, and vega collapses towards zero as expiry approaches. Our own capture shows a contract reading 244% at 15:15 on an expiry day and 0% fifteen minutes later. Both are the solver failing, not the market.
Written and maintained by MarketCue research
How these figures are produced
Every price on these pages was traded on the exchange and is read from our own option-chain capture, which records the NIFTY and SENSEX chains once a minute through the session. Each page names the session its figures come from.
Figures that a model produced rather than the market — the Greeks, implied volatility — are labelled as model outputs wherever they appear, and never presented beside traded prices without saying which is which. The pricing is checked against published reference values on every change.
Where our own data cannot support a claim, the page says so instead of generalising. MarketCue is not a registered investment adviser, research analyst or broker under SEBI regulations.