Protective Put: How to Hedge Your Stock Portfolio Using Index Puts

The two legs of a protective put

A protective put combines:

• Long stock or portfolio. Either an individual equity holding or a basket of stocks that broadly tracks an index such as Nifty 50 or Bank Nifty.
• Long put option. A put on the same underlying (for an individual stock hedge) or on a correlated index (for a portfolio hedge). The put gives you the right to sell the underlying at the strike price on or before expiry.

The combined position has a payoff that resembles long stock for prices above the put strike, but is floored at the strike for prices below it. The put acts as a price floor, exactly as insurance acts as a loss cap. The premium paid is the cost of the insurance.

The insurance analogy

The protective put is most easily understood by analogy to motor or health insurance. The underlying is your asset (the car, your health, your equity portfolio). The premium is the recurring payment you make to the insurer. The strike is the deductible equivalent — losses above the strike are absorbed by you, losses below are absorbed by the put.

Just as motor insurance does not stop accidents — it only limits the financial impact of one — a protective put does not stop the stock from falling. It ensures that your loss on the position cannot exceed a known maximum. In all the years where no significant decline materialises, the premium is paid and not recovered. In rare years where a sharp drawdown occurs, the put may pay back many years of premium in a single position. The economic distribution is asymmetric and rare-event-driven, just like real insurance.

Mechanics: an illustrative portfolio hedge

Suppose you hold an Indian equity portfolio of illustrative value Rs 10 lakh that closely tracks Nifty 50 (beta close to 1). Nifty spot is at an illustrative level of 22,500. You decide to hedge by buying one lot of the Nifty 22,000 PE (put expiry) at an illustrative premium of Rs 200 per unit. The Nifty options lot size is 50 (illustrative — NSE has revised lot sizes periodically, so check the current value).

• Hedge notional: 22,000 × 50 = Rs 11 lakh — a slightly larger floor than the portfolio value, reflecting the difference between the strike and the spot.
• Premium paid: 200 × 50 = Rs 10,000.
• Premium as % of portfolio: Rs 10,000 ÷ Rs 10,00,000 = 1.0%.
• Approximate maximum loss (if Nifty falls sharply below 22,000 and portfolio tracks index): (Portfolio decline at 22,000) + premium = approximately Rs 22k + Rs 10k = Rs 32k, equivalent to about a 3.2% loss before put payoff begins to fully offset further declines.

The 1% cost figure is illustrative. Premiums depend heavily on implied volatility, time to expiry, and how far OTM the strike is. During calm markets, hedge cost has historically been lower; during stressed periods (high VIX), the same nominal hedge can cost two or three times as much in premium percentage terms. This is precisely why insurance is most expensive when fear is highest — the option market prices the higher probability of claims into the premium.

Beta-adjusted hedge sizing

The simple sizing above assumed a portfolio beta of 1. In practice, equity portfolios have varying betas — a portfolio tilted toward small-cap or financials may have beta substantially above 1, while a defensive consumer-staples or pharma-heavy portfolio may have beta below 1.

The beta-adjusted hedge size is:

Number of index put lots = (Portfolio value × Portfolio beta) ÷ (Index level × Lot size)

For example, if the portfolio above had a beta of 1.3, the hedge would scale up to 1.3 lots (rounded up to 2 lots in practice for full coverage, or accept 1 lot of partial coverage). If beta were 0.7, the hedge would scale down to 0.7 lots — in practice, 1 lot provides over-coverage. The beta is itself an estimate based on historical regression of portfolio returns against index returns; it is not a constant.

Portfolios concentrated in one or two stocks generally hedge better with single-stock puts on those names, since index puts will not protect against idiosyncratic single-stock declines. Index puts protect against systemic moves, not company-specific shocks.

The payoff diagram

The protective put combines two payoffs:

• Long stock/portfolio: linear and unbounded in both directions.
• Long put: kinked. Below the strike, the put gains Rs 1 for every Rs 1 below the strike. Above the strike, the put expires worthless and only the premium is lost.

The combined position is shaped like a hockey stick: linear long exposure above the strike (offset down by the premium), flat below the strike (the put gain offsets further portfolio losses one-for-one). The line never recovers the premium paid in prices below where the upward leg crosses break-even (strike + premium for the put plus the original portfolio cost basis calculus).

When protective puts have historically been used

Educational literature and historical practice associate protective put usage with:

• Elevated implied volatility followed by perceived risk events. High VIX environments around budget days, general elections, US Federal Reserve meetings, RBI policy decisions, geopolitical flare-ups, or major earnings have historically attracted hedge demand. The option market prices in the expected event volatility, but for a holder unwilling to sell underlying positions, paying the premium can be preferred to liquidating.
• Tax-deferral situations. If selling shares would crystallise large taxable gains, buying puts as a hedge preserves the tax position. The hedge is a substitute for sale without realising the gain.
• Concentrated single-stock positions.ESOP holders, founders, and large position holders who cannot or do not wish to sell have historically used single-stock puts (on F&O-eligible stocks) to floor losses on a position they must continue holding for legal, contractual, or strategic reasons.

The cost-benefit problem

The fundamental difficulty with protective puts is that the insurance is never free. Unlike covered calls, where the premium flows to you, protective puts require paying premium continuously to maintain coverage. Over many years, the cumulative premium paid can exceed the realised drawdown protection, especially in extended bull markets.

Studies of always-hedged equity strategies have historically shown that perpetual protective put buying has materially lagged unhedged equity in normal market conditions. Selective hedging — buying puts only at perceived high-risk junctures — has produced mixed historical results because timing such junctures is itself a difficult forecasting problem. This is why the strategy is discussed in this article as one tool among many, not as a universally favourable position.

Strike selection

The choice of strike controls how much insurance you buy:

• At-the-money (ATM). Strike near the current spot. Maximum coverage — losses are capped almost at current levels — but the premium is the highest. Useful in extreme risk-off scenarios where any decline is unwanted.
• Slightly OTM (2-5% below spot). Cheaper premium, but the first 2-5% of any decline is unhedged. The most commonly discussed compromise in educational literature.
• Deep OTM (10-15% below spot).Inexpensive, sometimes called "catastrophe insurance." Pays off only in severe drawdowns. Suitable when the concern is a tail event rather than ordinary fluctuation.

The Greek Delta is sometimes used as a sizing guide. A 0.30 Delta put is roughly 30% likely to finish ITM under standard pricing assumptions; a 0.10 Delta put is roughly 10% likely. Detailed Greek behaviour is in our Option Greeks Explained article.

Rolling protective puts

Because options expire, a sustained hedge requires periodic replacement. As the current put approaches expiry, the holder must decide:

• Roll into the next expiry. Sell the current put (recovering any residual premium) and buy a new put on the next monthly or quarterly expiry. The new strike is typically chosen relative to the current spot, which means after a rally the new strike is higher and the absolute hedge level re-anchors upward.
• Allow expiry without replacement. Accept that the portfolio is now unhedged until a new put is bought. This is a deliberate decision, often made when premiums have become expensive or when the perceived risk window has closed.

Rolling has costs: brokerage, STT on sell-leg of the old put, STT on buy-leg of the new, GST, stamp duty, and the bid-ask spread on each leg. A monthly rolled put portfolio incurs twelve full round-trips per year — these costs need to be included in any honest assessment of the hedge.

The costless collar concept

A natural extension of a protective put is the collar: combine the long put (downside protection) with a written call (upside cap). The premium received from the short call partially or fully offsets the premium paid for the long put.

When the strikes are chosen so that the call premium received exactly equals the put premium paid, the structure is called a costless collar. The portfolio is fully insulated below the put strike and gives up all upside above the call strike, with no net premium outlay. Between the two strikes it behaves like long stock.

The trade-off is explicit: in exchange for free downside protection, you cap your upside. This is conceptually identical to combining the strategies in our covered call and protective put articles into a single position. Costless collars have historically been used by long-term holders who want to defer selling but accept a bounded payoff over a fixed horizon.

Tax treatment in India

Premiums paid for long puts, and any losses or gains realised when those puts are sold or exercised, typically flow through the F&O income line as non-speculative business income for most active participants. Losses on a put that expires worthless can usually be set off against other F&O profits and carried forward under non-speculative business loss rules.

For a single-stock protective put on a long-term equity holding, the put's P&L is on the F&O account while the underlying shares remain on the capital account — the two are accounted separately. Care is required to avoid mixing them. Personal classification depends on filing status, total income, and trading frequency. A SEBI-registered investment adviser or chartered accountant should be consulted for personal circumstances.

Indian context: instrument choice

Indian investors have several put instruments available for hedging:

• Nifty 50 puts. Highest liquidity in Indian options markets. Weekly and monthly expiries. Best instrument for hedging diversified large-cap-tilted portfolios.
• Bank Nifty puts. High liquidity. Suitable for hedging financial-sector-heavy portfolios; correlation with general market is high but not perfect, so basis risk exists for non-financial portfolios.
• Nifty Next 50 / Sensex puts. Available but less liquid.
• Single-stock puts.Available on the F&O list. Best for concentrated single-stock positions, but illiquidity and physical settlement at expiry are real considerations.

Related tools and further reading

To understand the option mechanics underlying the strategy, see our Options Basics India article. For Greeks behaviour around put strikes, see our Option Greeks Explained article. For the income-side companion strategy that combines with this one to form a collar, see our covered call guide.

This article is educational only and does not constitute investment advice or a solicitation to trade derivatives. Options trading involves substantial risk of loss. Hedging strategies have ongoing premium costs that reduce returns in benign market environments. Past market behaviour is not indicative of future results. Please consult a SEBI-registered investment adviser before making any trading decision.