Put Ratio Spread
A net-short-puts structure with a credit, a profit tent, and a large finite downside.
Quick Answer
A Put Ratio Spread buys one put and sells two lower-strike puts of the same expiry, usually for a net credit; because it is net short one put, the worst case is a large but finite loss if the underlying collapses toward zero.
Put Ratio Spread: key takeaway
A Put Ratio Spread pays a small credit for a bet on a mild fall that stalls at the short strike, hiding an uncovered short put whose loss runs toward zero — large but finite, unlike the call ratio spread's genuinely unlimited tail, and unlike a backspread's defined risk.
Put Ratio Spread at a glance
| Category | Spread Strategies |
|---|---|
| Market outlook | Neutral |
| Risk | Undefined risk |
| Net flow | Credit |
| Difficulty | Advanced |
| Legs | Buy 1 higher-strike put + sell 2 lower-strike puts, same expiry |
| Max profit | ₹413/unit · ₹26,845 per lot |
| Max loss | ₹23,287/unit · ₹15,13,655 per lot (only if the underlying reaches zero) |
| Breakeven | 23,287 |
Put Ratio Spread in simple words
You buy one put and sell two lower puts, usually taking in a small credit. If the market drifts down to the lower strike you do well, because the put you own gains while the two you sold have not yet turned against you. Below that strike the extra sold put has no cover, and your loss grows as the market keeps falling. The loss is not literally infinite — the market can only fall to zero — but the worst case is enormous. This is a bet on a mild fall that stalls, and it hides a large open-ended-feeling risk if the decline runs on.
Payoff diagram
Profit & loss at expiry — Put Ratio Spread
| Leg | Action | Type | Strike | Premium | Qty |
|---|---|---|---|---|---|
| 1 | Buy | Put | 24,000 | ₹309 | 1 |
| 2 | Sell | Put | 23,700 | ₹211 | 2 |
Put Ratio Spread: professional explanation
Undefined-risk, but finite at the bottom
The position holds one long put and two short puts of a lower strike. Above the short strike the long put and one short put broadly offset. Below the short strike, only one of the two short puts is covered by the long put — the second is naked. A naked short put loses as the underlying falls, but unlike a naked call it does not lose without limit: the underlying can fall only to zero. So the risk is undefined in the schema sense — nothing in the structure caps it, only the underlying running out of room — yet the worst case is a large finite number, not the unlimited loss of a call ratio spread. Write it as a loss all the way to zero, never as unlimited.
The profit tent points down
At expiry the payoff is a tent whose peak sits at the lower short strike, where the long put is fully in the money and both short puts are worthless. From the credit at high prices the profit rises to that peak, then falls as the underlying drops further and the naked put bites, crossing zero at the lower breakeven and deepening toward the worst case near zero. The peak equals the strike width plus the credit. The trade wants the underlying to settle at the short strike; it fears a continued collapse below the lower breakeven.
Not a backspread, and not unlimited
Two confusions to clear at once. First, this is a ratio spread, not a put backspread: it sells two and buys one, so it is net short and undefined-risk, whereas a put backspread buys two and sells one and is net long, defined-risk, and profits from a crash. Second, its worst case is finite. The call ratio spread's tail is genuinely infinite because the underlying can rise without bound; the put ratio spread's tail stops at zero. Both are undefined-risk, but only the call version is truly unlimited — a distinction worth stating precisely.
Margin, assignment and the crash scenario
The uncovered short put attracts naked-option margin, which is high and rises as the underlying falls toward the short strike. On stock options either short put can be assigned early, and below the strike the naked one delivers long stock at the strike with a paper loss and a cash outflow. On cash-settled index options there is no assignment, but a gap-down through the short strike can produce a large settlement loss with no chance to manage it. Because equity crashes are fast and correlated with volatility spikes, the put ratio spread's worst case tends to arrive quickly and all at once.
Construction
- Buy one higher-strike put of the chosen expiry.
- Sell two lower-strike puts of the same expiry, typically taking in a net credit.
- Recognise that one of the two short puts is uncovered, so the downside loss runs toward the underlying reaching zero.
Market outlook
A trader may study a put ratio spread when expecting the underlying to drift down modestly toward a support level and stall, with implied volatility rich enough that the two short puts fund the long one for a credit. The peak sits at the lower short strike. The view is invalidated by a continued fall below the lower breakeven, where the uncovered put produces a large loss toward zero, or by a volatility spike that inflates the short puts. Because equity declines are often fast and volatile, the failure mode can arrive abruptly, so the structure demands a firm floor on how far the underlying can fall and active management.
Risk profile
This is an undefined-risk position: nothing in the structure caps the loss below the short strike, because one of the two short puts is uncovered. The loss deepens all the way down as the underlying falls, stopping only when the underlying reaches zero — a large but finite worst case, not the genuinely infinite loss of a call ratio spread. On the upside the risk is limited to a small loss or the credit. The defining feature is the naked short put and the loss-toward-zero it carries, which is why margin is charged as if on a naked position rather than a hedged spread.
Maximum loss, stated three ways
As a formula: Large but finite: the loss deepens all the way to the underlying reaching zero, where it equals (long strike − 2 × short strike + net credit) × lot size in magnitude. Not unlimited — the underlying cannot fall below zero.
Computed from the illustrative legs: ₹23,287 per unit, i.e. ₹15,13,655 for one NIFTY lot of 65.
Breakeven: Lower breakeven = short strike − (strike width + net credit) per unit. An upper breakeven exists only if the trade is opened for a net debit. → 23,287.
Reward profile
The maximum profit is the strike width plus the net credit, reached only if the underlying settles exactly at the lower short strike at expiry, where the long put is fully valued and both short puts expire worthless. Away from that peak the reward falls off — toward the credit above the long strike and toward a large loss below the lower breakeven. The reward is concentrated at one price and sharply path-dependent, the price of accepting a loss that runs toward zero.
Maximum profit
As a formula: (Strike width + net credit) × lot size, reached only if the underlying settles exactly at the lower short strike at expiry.
Computed from the illustrative legs: ₹413 per unit, i.e. ₹26,845 for one NIFTY lot.
Margin requirement
Because one short put is uncovered, brokers and the exchange charge naked-option margin on the unhedged leg, so the requirement is high and rises as the underlying falls toward the short strike. SPAN plus exposure can increase intraday, particularly during volatility spikes. This is not defined-risk for margin purposes. NSE and brokers revise margin rules periodically, so confirm the current requirement before trading.
Greeks exposure
Small near initiation and turning increasingly positive as the underlying falls past the short strikes, because the position is net short one put on the downside.
Net short: the two short puts dominate, so gamma is negative and the delta deteriorates rapidly on a fall toward and beyond the short strike.
Positive: with more options sold than bought, time decay works for the position while the underlying stays above the short strike.
Net short: two short puts outweigh one long put, so rising implied volatility hurts and falling volatility helps.
Mildly positive on balance; minor for short-dated positions.
The sign on each Greek above is computed, not asserted: it is the net exposure of the illustrative legs at spot 24,000 with 30 days to expiry, priced with Black–Scholes using each leg's implied volatility calibrated from its own quoted premium. A sign can flip as the underlying moves — the panels below show where. See Methodology.
Net Greeks across underlying prices
Volatility impact
The position is net-short vega, so rising implied volatility works against it — the two short puts inflate faster than the single long put. This is especially punishing on the downside because equity falls are typically accompanied by sharp volatility spikes, so vega and direction turn hostile together exactly when the naked put is threatened. Falling volatility helps and is part of why the trade is opened when premiums are rich. But favourable volatility does not remove the structural risk: a continued decline below the lower breakeven still produces a large loss toward zero regardless of what volatility does.
Sensitivity to implied volatility
Time decay
Time decay works for the position while the underlying stays above the short strike, because more options are sold than bought and net theta is positive. Each quiet day erodes the two short puts in the trader's favour faster than the long put, which is why the tent peaks at expiry. Near expiry, with the underlying close to the short strike, negative gamma is large — small moves swing profit and loss sharply, and a late break below the strike converts a decaying winner into a rapidly deepening loss.
Value of the position as expiry approaches
Put Ratio Spread: practical examples
NIFTY example
Buy one 24,000 put at ₹309 and sell two 23,700 puts at ₹211 each. Cash in is 2 × 211 − 309 = ₹113 credit per unit, or ₹113 × 65 = ₹7,345 for one lot. The peak is at 23,700, where the long put is worth ₹300 and both short puts expire worthless: profit = (300 + 113) × 65 = ₹26,845. The lower breakeven is 23,700 − 413 = 23,287. The worst case is finite: at a notional zero the long put is worth 24,000 and the two shorts 47,400, so the payoff is 24,000 − 47,400 = −23,400, plus the ₹113 credit = −₹23,287 per unit, or −₹15,13,655 per lot — vast, but not unlimited.
BANKNIFTY example
Illustrative BANKNIFTY, spot ~52,000, lot 30: buy one 52,000 put at ₹640 and sell two 51,500 puts at ₹430. Credit = 2 × 430 − 640 = ₹220 per unit = ₹220 × 30 = ₹6,600. Peak at 51,500: (500 + 220) × 30 = ₹21,600. Lower breakeven 51,500 − 720 = 50,780. Below it the loss deepens toward, but never past, the underlying reaching zero — a large finite worst case, not unlimited. Premiums are illustrative; lot size is as as of July 2026.
Lot sizes used above (NIFTY 65, BANKNIFTY 30) are those in force as of July 2026; NSE revises them periodically. Figures exclude brokerage, STT, exchange charges, stamp duty and GST, all of which materially affect small spreads.
Common misconceptions about Put Ratio Spread
- Misconception: A put ratio spread's loss is unlimited, like a call ratio spread's.
Reality: No. Unlike a call ratio spread, whose loss is genuinely infinite on a rally, a put ratio spread's loss is bounded by the underlying reaching zero. It is undefined-risk and very large, but finite. Describe it as a loss toward zero, not as unlimited. - Misconception: A put ratio spread is safe because it takes in a credit.
Reality: No. It collects a credit and decays in your favour, which feels safe, but one of the two puts you sold is uncovered. A continued fall produces a large loss that can arrive fast in a crash. It needs active management.
Common mistakes with Put Ratio Spread
- Calling the downside unlimited: it is a large but finite loss toward zero, and describing it as infinite confuses it with the call ratio spread, which genuinely is.
- Believing the credit measures the risk, when a continued fall below the lower breakeven produces a loss many times the premium collected.
- Confusing it with a put backspread: this sells two and buys one, so it is net short and undefined-risk, not the net-long, defined-risk backspread that profits from a crash.
- Ignoring that equity declines are fast and volatile, so the worst case can arrive abruptly on a gap-down with no chance to manage the naked leg.
- Underestimating the naked-option margin, which is high and rises as the underlying falls, potentially forcing an exit at the worst moment.
- On stock options, overlooking early assignment of a short put, which below the strike delivers long stock at the strike with an immediate paper loss and cash outflow.
Advantages & disadvantages
Advantages
- It can be opened for a credit, so a market that holds above the short strike returns the premium with no move needed.
- The peak profit near the short strike is large relative to the credit, rewarding a correct read on where the underlying settles.
- Time decay and falling implied volatility both work for the position while the underlying stays above the short strike.
- Its worst case, though large, is finite — bounded by the underlying reaching zero — unlike the genuinely infinite tail of a call ratio spread.
- It expresses a precise view — a modest drift down that stalls at support — that few simpler structures capture as cleanly.
Disadvantages
- The downside loss runs all the way toward the underlying reaching zero, a large figure that dwarfs the credit.
- Margin is naked-option margin, high and liable to rise as the underlying falls toward the short strike.
- Rising implied volatility hurts, and volatility spikes typically accompany the falls that threaten the naked put.
- The full profit occurs only at a single price, so the reward is sharply path-dependent.
- Because equity declines are fast, the failure mode can arrive abruptly, leaving little room to adjust.
Adjustments & exits
- Buying a further-out put against the naked short converts the position into a defined-risk structure such as a put broken-wing butterfly, at the cost of some credit.
- Rolling the short puts down and out as the underlying falls lowers the danger zone, but adds risk and does not guarantee escaping the tail.
- Closing one of the two short puts removes the uncovered leg, leaving a plain bear put spread with defined risk and a smaller position.
- Taking the whole trade off as the underlying approaches the short strike near expiry avoids the violent gamma and the deepening loss below it.
Adjustment is a decision about risk, not a way to rescue a losing view. See Adjustments and Exit Planning.
How professionals use the Put Ratio Spread
Volatility desks use put ratio structures to shade downside exposure and monetise a rich put skew, usually as part of a larger managed book rather than a standalone bet, hedging the uncovered wing with futures or further options as the market moves. The credit and negative vega express a view that the underlying eases toward support and volatility softens, with the tail controlled by size limits. For a retail trader, the fast, correlated nature of equity declines and the rising naked margin make the uncovered leg difficult to manage, so the structure is among the less forgiving to carry through a falling market.
Put Ratio Spread: frequently asked questions
What is the maximum profit on a put ratio spread?
The strike width plus the net credit, times the lot size — (300 + 113) × 65 = ₹26,845 in the NIFTY example. It is reached only if the underlying settles exactly at the lower short strike, where the long put is fully valued and the shorts expire worthless.
What is the maximum loss on a put ratio spread?
A large but finite loss, deepening as the underlying falls and reaching its worst at a notional zero — about ₹23,287 per unit, or ₹15,13,655 per lot, in the NIFTY example. It is not unlimited, because the underlying cannot fall below zero.
Is a put ratio spread the same as a backspread?
No, they are opposites. A ratio spread sells two and buys one, is net short, takes a credit and is undefined-risk. A put backspread buys two and sells one, is net long, pays a debit and has defined risk with large profit on a crash.
Where is the breakeven on a put ratio spread?
The lower breakeven is the short strike minus the width minus the credit — 23,700 − 413 = 23,287 in the NIFTY example. Below it the position loses. If opened for a debit rather than a credit, an upper breakeven also exists.
Why is a put ratio spread undefined-risk if the loss is finite?
Because nothing in the structure caps the loss — only the underlying running out of room at zero does. That is the schema meaning of undefined-risk. The loss is finite in size but structurally uncapped, which is why it attracts naked-option margin.
Can a put ratio spread lose more than its credit?
Yes, far more. A continued fall below the lower breakeven produces losses that can reach many times the credit, up to the large finite worst case near zero. Treating the credit as the risk is the central mistake with this structure.
What margin does a put ratio spread need?
Naked-option margin on the uncovered short put, not spread margin, so the requirement is high and rises as the underlying falls toward the short strike. Confirm the current NSE and broker rules, as margin on undefined-risk positions is revised periodically.
Does high implied volatility help a put ratio spread?
At entry it fattens the credit, and the position is net-short vega, so it benefits if volatility then falls. But volatility spikes usually accompany the falls that threaten the naked put, so the volatility comfort is secondary to the downside risk.
Put Ratio Spread: voice-search questions
Natural-language questions people ask about the Put Ratio Spread.
What is a put ratio spread?
It is an options trade where you buy one put and sell two lower puts, usually for a small credit. You profit if the market drifts down and stalls near the lower strike, but you carry a large loss toward zero if the market keeps falling.
Is a put ratio spread the same as a put backspread?
No, they are opposites. A ratio spread sells two and buys one, is net short and undefined-risk. A put backspread buys two and sells one, is net long and defined-risk, and it profits from a crash rather than fearing one.
When would I use a put ratio spread?
When you expect the market to ease down to a support level and stall, and you are willing to carry uncovered downside for a credit. If you fear a crash, this is the wrong structure — a backspread or a defined-risk spread fits that view better.
People also ask about Put Ratio Spread
Questions answered in depth on their own pages:
Sources & references
Published 9 July 2026. Educational content only — not investment advice.