Basically, a put option allows someone to “lock in” the sale price of an asset. If someone owns a put option, they can force someone else to purchase an asset at a set, pre-defined price.
That agreed-upon price is known as the “strike price” and is defined in the option contract.
The actual market price of that asset might end up being significantly lower than the strike price, but the put option has locked in the sales price.
Put Option — Falling Stock Price Scenario
There are two scenarios that are important to consider at this point: falling stock price vs. rising stock price.
Let’s look at the following ‘falling stock price’ example:
Assume the stock in XYZ Corp is trading for $100 per share on January 1st. Someone decides to buy a put option with a $100 strike price and a three-month expiration. Then, let’s assume by March 31st the price of XYZ Corp’s stock has fallen to $60.
The owner of the put option has locked in a sales price of $100, even though the market price of XYZ is only $60.
Someone else has to pay him the full $100 for XYZ stock.
Not bad! That’s a difference of $40.
Of course, it goes without saying that put options are not free. In the scenario above, the holder of that put option might have paid $5 for his three-month put option on XYZ on January 1st. That out-of-pocket cost would reduce the profit from $40 to $35 in the above scenario.
But what if the price of XYZ stock goes up, rather than down?
What if over the next three months the price of XYZ rises from $100 to $125 per share?
Put Option — Rising Stock Price Scenario
Again, the put option gives the investor the chance to sell XYZ for the locked-in price of $100. But the market price is now $125! The investor could sell XYZ on the open market and collect $125. The fact that he has a put option at $100 is now irrelevant and the put option, at expiration, is worthless.
Back in January, the investor did not know if XYZ was going to go up or down, but he had to pay that $5 premium to purchase the put option regardless. The holder of the put option hopes that XYZ falls far enough so that the gap between the strike price and the market price is at least enough to cover the $5 out-of-pocket costs he had when purchasing the put option. If that gap is larger than $5, then the remainder is all profit to him. However, if XYZ is flat or rises, then the option will eventually expire and the investor will be out $5.
It should be noted that all options eventually expire. Some expire after only a week, some might have expiration dates going out for two or three years.
The time to expiration impacts the price someone might pay for an option. Generally speaking, the longer to expiration, the more valuable the option is since there is more time for a move to occur.