Mechanics · Lesson 03 of 4 · Lab
Mark to market and P&L
Option positions are revalued at the end of every session, and for written positions the change is settled in cash daily rather than at expiry. A position that finishes profitable can require funding along the way: the NIFTY 23,450 straddle written on 22 September 2026 collected ₹99.35 and closed the session ₹21.85 down.
NIFTY weekly expiry, 22 September 2026 · MarketCue one-minute option-chain capture
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Prices captured at the open on Tuesday, 22 September 2026. NIFTY spot at the open: 23,460. The highlighted row is nearest the money.
NIFTY closed at 23,329, down 131 points from the open. Sold 23,450 CE at ₹64.50 → settled ₹0.05. Sold 23,450 PE at ₹34.85 → settled ₹121.15. Net loss of ₹21.85 per unit, or −22% of what was put up. This was the expiry, so those closing prices are settlement values.
Buyers and writers are billed differently
An option buyer pays the premium at the outset and is never asked for anything else. Whatever happens next, the maximum outlay is already known and already paid. The position is revalued daily, but the revaluation does not generate a cash call.
A writer is in a different position. The premium arrives at the outset, margin is blocked against the obligation, and the position is marked to market at the end of each session — with losses settled in cash and margin requirements recalculated as volatility and the position’s risk change.
That daily settlement is why a written position can be solvent at expiry and still fail before it: the funding requirement is a sequence, not a single number at the end.
Following one position through the session
The written 23,450 straddle brought in ₹99.35 at the open. By the close the call had settled at ₹0.05 and the put at ₹121.15, so the position was worth ₹121.20 against the ₹99.35 received — a mark of ₹21.85 against the writer.
On this session that was also the final outcome, because 22 September was the expiry. On any other day it would have been an interim figure: cash settled that evening, with the position still open and the margin requirement recomputed for the next morning.
Switch to the bought-call preset for the contrast. The buyer paid ₹64.50, the contract settled at ₹0.05, and no further cash moved at any point.
Common questions
What is mark to market in options?
Daily revaluation of an open position against the closing price. For written positions the change is settled in cash each evening and margin requirements are recalculated; option buyers pay their premium once and face no further calls.
Can I lose more than the premium on an option?
Not as a buyer — the premium is the maximum loss. As a writer, yes: the obligation is open-ended beyond the breakeven, margin is blocked against it, and losses are settled daily rather than at expiry.
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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.