Single options

Bearish, or a hedge

Debit

Risk: Defined: the premium paid

Long put

Also called: Buy put, PE buy

Buy one put option: gains when the underlying falls below the strike by more than the premium; the premium is the most you can lose.

Payoff sketch (per unit, index points)

At expiry

Today (7 days left)

Net premium

Debit 164 pts

Max profit

Large as the price falls

Max loss

−164 pts (₹10,679 per lot)

Breakeven

24,836

Legs: Buy PE ATM. Illustration, not live prices: an index at 25,000, strikes 100 points apart, Black-Scholes premiums at 13% implied volatility, 7 days to expiry, 6.5% interest, no skew and before charges. Rupees per lot use a NIFTY lot of 65.

How it works

A put is worth the amount by which the underlying settles below the strike at expiry. Before expiry it also carries time value, which decays daily.

Puts on an index are also bought as insurance for a portfolio or a long futures position: the premium is the cost of the cover, and it is lost if the fall never comes.

When traders use it

A view that the price will fall by more than the premium before expiry, with the loss capped.
Protection for long stock or futures holdings against a sharp fall.

Greeks

Delta	Negative: about −0.5 at the money, moving toward −1 in the money and toward 0 out of the money.
Gamma	Positive, largest at the money near expiry.
Theta	Negative: time value decays daily, fastest in the final days.
Vega	Positive. Index puts usually trade at a higher implied volatility than calls the same distance away (the skew), so they are comparatively expensive.

Profit, loss and margin

Max profit	Large but finite: (strike − premium) × quantity if the underlying went to zero; in practice the size of the fall below the breakeven.
Max loss	The premium paid plus charges, if the underlying settles at or above the strike.
Breakeven	Strike − premium paid (a little lower after charges).
Margin	No margin: the premium is paid in full upfront.

In India

Buyers pay the full premium upfront and need no further margin; the most they can lose is the premium plus charges.
A long option that finishes in the money is exercised automatically. STT is then charged on its intrinsic value at the exercise rate (0.15% from 1 April 2026 in Arthfy's cost model), instead of the sale rate on the premium (also 0.15%) that applies when the option is sold before the close. See the lesson on the STT exercise trap.
Since 20 November 2024 each exchange keeps one weekly index expiry: NIFTY on NSE and SENSEX on BSE. Since September 2025 NSE contracts expire on Tuesdays and BSE contracts on Thursdays. BANKNIFTY, FINNIFTY, MIDCPNIFTY and stock options expire monthly (NSE on the last Tuesday). A holiday moves the expiry to the previous trading day.
Contracts trade in exchange-set lots. As of October 2026: NIFTY 65, BANKNIFTY 30, FINNIFTY 60, MIDCPNIFTY 120, SENSEX 20, and typically a few hundred shares for a stock. Lots are revised from time to time, so check the live lot before sizing.

Arthfy numbers

Long put: what it did since 2016

Long put, at the money, entered 8-15 days before expiry.

0-2 d

3-7 d

8-15 d

16-30 d

31-45 d

Try it in the F&O hub

Opens the tool with this structure on today's NIFTY chain. Reading is free with an Arthfy account; some runs use free attempts.

Open in the builderPayoff, Greeks, scenario grid and charges on today's NIFTY chain

Backtest since 2016Daily data, every NIFTY expiry

Replay on expiry daysMinute data since October 2024

Open the option chainLive premiums, IV and Greeks

Single options

Put ratio backspread

For education: how the structure works and what it did historically, not a recommendation to trade it.