Buying and Selling Put Options

Buying a put option gives you the right to sell 100 shares of a stock at a fixed price, the strike, any time before the option expires. You pay a premium up front to hold that right, and that premium is the most you can lose. Selling a put you already own, called selling to close, means handing the same contract back to the market before expiry and collecting whatever it is worth at that moment.

This post follows one real contract the whole way: the SPY $740 put expiring June 18, 2026. Watching it move teaches every part of the round trip.

What happens when you buy a put option

When you buy a put, three numbers define the trade before it starts.

• The premium is what you pay. On Jun 4 this SPY put closed at $2.75, with SPY up at $754.56, well above the $740 strike. The put was entirely a bet that SPY would fall.
• The maximum loss is that premium, and nothing more. Buy the put at $2.75 and the worst case is the $2.75 you paid, however high SPY climbs. A long put cannot cost you more than you put in.
• The breakeven at expiry is the strike minus the premium. Pay $2.75 for the $740 put and the position turns a profit at expiration only once SPY sits below the $740 strike by more than that premium. Above it, the put expires worthless.

A long put is insurance with an expiry date. You pay a known amount for the right to sell at $740, and the clock is always running against you.

The round trip: one real SPY put

Here is the put's entire life, from deep in the money in early May to its final week:

SELECT date,
       formatDateTime(date, '%b %e') AS label,
       round(avg(option_close), 2) AS put_price
FROM global_markets.options_greeks
WHERE ticker = 'O:SPY260618P00740000'
  AND date BETWEEN '2026-05-01' AND '2026-06-15'
  AND implied_volatility > 0.02
GROUP BY date
ORDER BY date

And the stock it tracks, over the same weeks:

SELECT date,
       formatDateTime(date, '%b %e') AS label,
       round(avg(underlying_close), 2) AS spy_price
FROM global_markets.options_greeks
WHERE ticker = 'O:SPY260618P00740000'
  AND date BETWEEN '2026-05-01' AND '2026-06-15'
  AND implied_volatility > 0.02
GROUP BY date
ORDER BY date

Read the two charts together. On May 1 the put was worth $23.05, with SPY down at $720, below the $740 strike, and the put carried real intrinsic value. As SPY climbed through May toward its $759.63 high on Jun 2, the put melted to $2.79. A put loses value as the stock rises above the strike.

Then SPY turned. From $754.56 on Jun 4 the stock fell to $722.88 by Jun 10, back below the strike. Over those same sessions the put ran from $2.75 to $18.7. A contract bought at $2.75 was worth $18.7 a week later.

Selling to close versus letting it decay

The gain on Jun 10 is only real if you act on it. Selling to close means selling the put back to the market that day and banking the $18.7 it is worth. You never own or deliver a single share; you simply exit the contract.

Holding instead exposed the position to two forces working against a put once the stock recovers. SPY rallied from $722.88 back to $753.91 by Jun 15, lifting the stock above the strike again. At the same time every passing day drained the option's remaining time value, the effect the greeks call option theta. By Jun 15 the put that had peaked at $18.7 was worth $1.16. The paper gain from Jun 10 was gone.

The lesson is not that holding is a mistake. A long option's value is a moving mark, and the profit exists only while the contract does. An option's expiration date sets the deadline, and every session inside it decay works against the buyer.

Buying puts for protection versus speculation

The same contract serves two very different purposes.

Speculation is the trade above: buy the put outright as a bet that SPY falls, risking the premium to capture a decline. The buyer on Jun 4 paid $2.75 for pure directional exposure.

Protection flips the intent. An investor already holding SPY shares can buy the same $740 put as insurance. When SPY drops, the shares lose value while the put gains, offsetting the fall below $740. The put's $18.7 peak on Jun 10 coincided with SPY trading at $722.88, well under the $740 strike. A protective put pays exactly when the portfolio hurts. The premium is the cost of that coverage, and it decays the same way whether you hold the put for insurance or for profit.

How expensive that insurance runs at any moment turns on implied volatility, the market's priced-in expectation for how much the stock will move. Fear raises put premiums; calm lowers them.

FAQ

What is the maximum loss when buying a put?

The premium you pay, and nothing more. A long put cannot lose more than its cost, no matter how far the stock rises. The SPY put above cost $2.75 on Jun 4, so $2.75 was the entire risk.

What does selling to close a put mean?

It means selling a put you already own back to the market before expiration, to collect its current value. You are closing the position, not opening a new short one. Whoever sells to close on Jun 10 banks the $18.7 the contract was worth that day.

How do you calculate the breakeven on a long put?

Subtract the premium from the strike. For a $740 put bought at $2.75, the position turns profitable at expiry only once the stock is below the $740 strike by more than that premium. Above the strike, the put expires worthless and the buyer loses the premium.

Why did the put lose almost all its value by the last day?

Two things moved against it at once. SPY rallied from $722.88 back above the $740 strike, and time decay drained the option's remaining value as June 18 approached. By Jun 15 the put was worth $1.16.

Is buying a put the same as short selling?

No. A long put risks only the premium and lasts until expiration, while a short stock position carries unlimited loss and no expiry. The put gives defined-risk downside exposure; short selling does not.

Run this contract's full history yourself on the Strasmore terminal and watch the round trip session by session.