Put Ratio
Back Spread

What is a put ratio back spread?

A put ratio back spread is a two-strike multi-leg strategy built from put options of the same expiry. You sell one higher-strike put and buy two lower-strike puts. The single short put pays for most of the two long puts, so the trade is usually opened for a small net credit or close to zero cost — yet it leaves you net long one put.

That net-long put is the whole point. If the underlying falls hard, the two long puts run faster than the one short put, and profit accelerates without a ceiling. If the underlying rises, all the puts expire worthless and you keep the credit. The only sore spot is a middle zone around the lower strike, where the short put bites before the long puts have caught up.

Key takeaways

• A put ratio back spread is a two-strike put structure: sell 1 higher put, buy 2 lower puts, same expiry.
• It is normally a credit or zero-cost trade, so a rally simply lets you keep the small credit.
• It delivers large, open-ended profit on a sharp fall because you are net long one put.
• The maximum loss is small and defined, occurring around the lower strike at expiry.
• It is a long-volatility position — rising implied volatility and a decisive move both help.

How a put ratio back spread works

Construction is a sold put financing two bought puts a step lower. Because you own one more put than you are short, the position has positive vega and net long delta to the downside: a jump in implied volatility lifts the long puts, and a fast drop sends the payoff sharply higher. This is the bearish mirror of a call ratio back spread.

The short put is the leg that draws margin. The exchange blocks SPAN + exposure margin on it, though the two long puts offset much of the requirement versus a naked short put. Theta works against you on balance — you own more options than you sold — so a quiet, drifting market that parks price near the lower strike is the unfriendly outcome. NIFTY and Bank Nifty legs are cash-settled at expiry.

The numbers that matter

Worked NIFTY example

Suppose NIFTY is near 22,500 and you fear a sharp slide but do not want to pay up for naked puts. You sell the 22,400 put at ₹130 and buy two 22,200 puts at ₹60 each. Net credit = 130 − (2 × 60) = ₹10. With a lot size of 75, you collect ₹10 × 75 = ₹750 up front (illustrative figures):

• Upside: above 22,400 all puts expire worthless — keep the ₹750 credit.
• Max loss: at 22,200 at expiry = (22,400 − 22,200 − 10) × 75 = −₹14,250.
• Lower breakeven: 22,200 − 190 = 22,010 — below this profit accelerates.

NIFTY at expiry	Outcome	P&L (1 lot)
22,600	All puts expire worthless	+₹750
22,400 (short strike)	All puts worthless	+₹750
22,200 (worst case)	Short put deep ITM, longs flat	−₹14,250
22,010 (lower B/E)	Long puts catch up	₹0
21,500	Sharp fall, net long one put	+₹38,250

Notice the asymmetry in your favour: a tiny credit on a rally, a contained loss in the middle, and a large open-ended gain if the fall is decisive. You are effectively paid a little to own crash insurance.

When to use a put ratio back spread

• You expect a large, fast move down rather than a gentle drift — direction and speed matter.
• Implied volatility is low and likely to spike, lifting your net-long puts.
• You want defined risk with a chance at open-ended downside profit, without paying full premium for naked puts.
• You are positioning ahead of an event or breakdown where a quiet outcome is unlikely.

Risks to respect

• Middle-zone loss: a slow drift to the lower strike at expiry produces the maximum loss — a non-event is the worst case.
• Theta bleed: you own net options, so holding through calm days erodes value daily.
• IV crush: a fall in volatility hurts the long puts even if you are eventually right on direction.
• Margin: the short put attracts SPAN + exposure margin and can be marked up as the trade moves against you.

Put ratio back spread vs bear put spread

A bear put spread buys one put and sells one lower put — defined risk, but the profit is capped at the strike gap. The put ratio back spread flips the leg count: it sells the higher put and buys two lower puts, leaving you net long. The reward on a sharp fall is open-ended instead of capped, paid for by accepting a small middle-zone loss. Use the bear put spread for a measured, capped-target view; use the back spread when you expect a violent breakdown.

Put ratio back spread vs long put

A plain long put is the simplest bearish bet — defined risk equal to the premium, large reward on a fall — but you pay full premium up front and time decay grinds against the single option. The put ratio back spread finances most of that cost by selling a higher put, often turning the trade into a credit, at the price of a defined loss zone in the middle. The long put is cleaner; the back spread is cheaper to carry but has a sting between the strikes.

Common adjustments

If the underlying parks near the lower strike as expiry nears, traders may roll the short put down to widen the loss zone, or close the spread for a small credit before decay does its worst. On a volatility spike with price still mid-range, booking the long puts and leaving the short to decay can salvage a profit. Because the worst case is a slow grind, size the position so the defined max loss is comfortable.

Frequently asked questions

Is a put ratio back spread bullish or bearish?

Bearish and long-volatility. It makes its biggest profit on a sharp fall, takes a small capped loss in the middle, and keeps a small credit if price rises.

What is the maximum loss on a put ratio back spread?

It is fixed and occurs at the lower strike at expiry — the gap between the strikes minus the net credit, times the lot size.

Why is it a long-volatility trade?

You are net long one put, so rising implied volatility and a large downside move both lift the position; the extra long put gives open-ended profit on a sharp fall.

How is it different from a bear put spread?

A bear put spread caps the profit; the back spread sells one put and buys two lower puts, leaving net-long exposure that profits without a cap on a sharp fall.

The bottom line

The put ratio back spread is a disciplined way to be long a crash. By selling one higher put to fund two lower ones, you usually open for a credit, keep that credit on a rally, accept only a small defined loss in the middle, and stand to make a large open-ended profit if the fall is sharp. The enemy is a quiet market that parks price near the lower strike. Treat it as a long-volatility, event-driven trade, size for the middle-zone loss, and let a decisive move pay you.

Related strategies & terms

• Bear Put Spread — the capped-profit, two-leg bearish cousin.
• Call Ratio Back Spread — the bullish mirror that profits on a sharp rally.
• Long Put — the simplest defined-risk bearish bet.
• Vega · SPAN Margin · Multi-leg