stock options – Economist Writing Every Day

This continues our occasional series on stock options for amateurs.

I find options to be a nice tool in my investing arsenal. The previous post in this series was Stock Options Tutorial 1. Options Fundamentals. That post dealt with buying options, to provide simple examples. For reasons to explained in a future post, I usually prefer to sell options. Anyway, here we will look briefly at how options are priced. It is important to get an intuitive understanding of this, in order to be comfortable actually using options in your account.

The current price of an option, if you wanted to buy or sell it, is called the premium. There are two components that go into the premium, the intrinsic value and the extrinsic (or “time”) value:

Source: OptionAlpha

Intrinsic Value of Options

The intrinsic value is easy to figure out, once you understand it. It is simply how much you would profit if you owned the option, and decided to exercise it right now. For instance, if you owned a call with a strike price of $50, but the stock price is $55, you could exercise the call and force whoever sold you the call to sell you the stock at a price of $50/share; you could turn around and immediately sell that share for $55, pocketing $5/share. We say that the option in this case is $5 in the money, and the intrinsic value is $5.

If the stock price were $60, it would be $10 in the money; you could pocket $10/share for exercising it. If the stock price were say $90, the option would be $40 in the money, and so on.

However, if the stock price were $50 (the $50 option is “at the money”) or lower (option is “out of the money”), you would get no benefit from being able to purchase this stock for $50, and so the intrinsic value of the option would be zero.

With a put (which is an option to sell a stock at a particular price), this is all reversed. If the stock is $5 lower than the option strike price, the option is $5 in the money and has a $5 intrinsic value, since if you own it, you could say buy the stock at $45, and force the put option seller to buy it from you at $50/share:

Source: OptionAlpha

Extrinsic (Time) Value of Options

Suppose the current price of a stock is $50. And suppose you suspect its price may be above $50, say $60 sometime in the next month, so you would like to have the option of buying it at $50 sometime in the future, and then selling it into the market at (say) $60, for a quick, guaranteed profit of $10. Sounds great, yes?

Since a $50 call is right at the money (since the stock price is also $50), the intrinsic value of a $50 call is zero. Does this mean you could go out and buy a $50 call option for nothing? No, because the seller of the option is taking a risk by providing you that option. If the stock really does go to $60, he could be out the $10. Therefore, he will demand a higher price than the intrinsic price, to make it worth his while. This extra premium over the intrinsic premium is the extrinsic premium, which varies greatly with the time till expiration of the option.

If you wanted the option of buying the stock at $50 sometime in the next week, the option seller would charge only a small amount; after all, what are the odds that the stock will rise a lot in one week? However, if you wanted to extend that option period out to one year, he will charge you a high extrinsic premium, since there is a bigger chance that the stock could soar will over $50 sometime in that long timeframe.

Another way of framing this is, if you buy a $50 call option today with an expiration date a year from now, you will pay a high extrinsic value. But as the months roll by, and it gets closer to the expiration date, this extrinsic value or time premium will shrink down ever more quickly towards zero:

Source: QuantStackExchange, on Seeking Alpha

Now, computing the actual amount of the extrinsic value is really gnarly. The Black-Scholes model provides a theoretical value under idealized conditions, but for us amateurs, we pretty much have to just take what the market gives us. In deciding whether to buy or sell an option, I look at what the current market pricing is for it.

It turns out that an option which is priced at the money has the highest extrinsic value. As you get further into or out of the money, the extrinsic component of the total premium for the option diminishes. Below is one final graphic which pulls all this together:

Source: OptionTradingTips

The call option strike price is $25. The blue line shows the intrinsic value (labeled as “payoff at expiration”) at each stock price – this is zero at or below $25, and increases 1:1 as the stock price climbs above $25. The red curve shows the full market price of the option, including the extrinsic (time) premium. The spacing between the red and the blue lines shows the amount of the extrinsic premium. That spacing is greatest when the stock price is equal to the $25 strike price. The shaded areas specify the intrinsic and extrinsic values at a stock price of $27.

And (not shown here) as time passed and the option got closer to expiry, the extrinsic value would shrink (decay), and the red curve would creep closer and closer to the blue curve.

Put simply, a stock option is a contract to buy (if it is a call option) or to sell (if it is a put option) a given stock at some particular price (“strike price”), by some particular expiration date.

Example: Buying Apple Call Option Instead of the Stock

In a little more detail: if you buy a call option on a stock, that gives you the right to buy that stock at the strike price (“call” the stock away from some current stockholder).
For most American stocks the option holder can exercise this right at any time, up till the end of the expiration day. (For so-called European options, you can only exercise the option on the expiration date itself.)
Let’s jump into an example. As of late morning 11/27/2023 when I am writing this, the price of Apple stock is $190 per share. Suppose I have a strong conviction that within the next month or so, Apple will go up by 10 dollars (5%) to $200/share.

One thing I can do is plunk down 100 x $190= $19,000 to buy 100 shares of Apple, and wait. If Apple does indeed reach my target price of $200 in some reasonable timeframe, and I sell it there, I will make a profit of 100 shares x $10 / share = $1000 on my initial investment of $19,000. That represents a 5.3% return on my investment.

But suppose because of some unexpected factor (Taiwan invasion?), that the price of Apple plunges by say 30% to $133/share, and remains there for the indefinite future. If I want to get my money out of this affair and move on, I would face a huge loss of 100 shares x (190-133)= $5,700 dollars on my large $19,000 investment.

Instead of buying the stock outright, I could buy a call option. There are a number of specific strategies and choices here, but to keep it simple, I could buy an Apple call option with a strike price of 190 (the current price of Apple) and an expiration date of say December 29, 2023. At the moment, that call option would cost me $3.80 per share, or $380 dollars for a standard options contract that involves 100 shares.

If Apple stock hits my price target of $200 sometime in the next month, I could exercise this option and purchase 100 Apple shares for $19,000 dollars, (100 x $ 190 strike price) and immediately sell them into the market 100 x $200/share = $20,000 dollars. That would give me a net profit of: (profit on stock buy & sell) minus (cost of call option) = 100 x ( ($200 – $190 ) – $3.80 ) = $620. That is a return of 163% on my $380 investment. Woo hoo!
(If I did not want to actually exercise the call, I could have sold it back into the options marketplace; the value of the call would have risen by somewhat less than $10 dollars since the time I bought it, so I could take my profit that way, without going through the cycle of actually buying the shares and immediately selling them.)

If Apple stock fails to rise by more than the $3.80 dollars a share that I paid for the call option, I will lose money on this trade. If Apple stays at or below 190, this call option expires valueless, and I will have lost 100% of my option purchase price. (If say two weeks goes by and the share price is hovering just below 190, this call option might still be worth something like $1.90/share, and I might choose to sell it and bail on this trade, to recover half of my $3.80 instead of risking the loss of all of it; there are many, many ways to trade options).

Now, in the event that Apple shares plunge by 30% and stay low indefinitely, I would only lose the $380 that the options cost me, instead of the $5,700 dollars I would lose if I had bought the stock outright.

This example demonstrates some of the benefits of buying stock options: You can make a huge return on your invested/risked capital if your stock price thesis plays out, and you can be shielded from any losses other than the cost of the option. The big weakness of this approach is that your hoped-for stock move must occur within a limited timeframe, before the expiration date, or else you can lose 100% of your investment. Folks who trade options for a living make lots and lots of small trades, knowing that they will lose on a significant percentage of these trades, hoping that their wins will outweigh their losses.

Buying Put Options for Hedging and Speculation

This has been a somewhat long-winded explanation of one way of utilizing options, namely, buying calls. Buying a put option, on the other hand, gives you the right to require that someone will buy a stock from you at the strike price (here, you are “putting” the stock to the person who sold you the option).

Puts are often used as for protective hedging. Suppose I own 100 shares of Apple stock that is currently valued at 190 dollars a share, and I want to protect against the effects of a possible plunging share price. As an example, I might buy a March 15, 2024 put with a strike price of 175, for $2.80. If Apple price falls, I would absorb the first 15 dollars per share of the losses, from 190 to the strike price of 175. However, that put would protect me against any further losses, since no matter how low the share price goes, I could sell my shares at $175. (Again, instead of actually selling my shares, I might sell the puts back into the market, since their value would have increased as Apple share price fell).
Buying puts in this manner is like buying insurance on your portfolio: it costs you a little bit per month, but prevents catastrophic losses.

Buying puts can also be used for speculative trading. Suppose I was convinced that Apple stock might fall well below $175 in the next three months. Without owning Apple shares, I might buy that March 2024 175 put for $2.80 per share, or $280 for a 100-share contract. If Apple share price went anywhere below (175 – 2.80 = 172.20), I would make money on this trade. If the price went back down to its recent low of 167, my net profit would be around 100 x (172.2 – 167) = $520. This would be nearly doubling the $280 I put into buying the puts. But again, if Apple price failed to fall as hoped, I might lose all of my $280 option purchase price.

Where to Find Options Prices

There are lots of YouTube tutorials on trading stock options. Here is quick ten-minute intro: Stock Options Explained, by The Plain Bagel. If you want to check out the prices of options, they are shown on websites like Yahoo Finance, Seeking Alpha (need to give email to sign in; you can ignore all the ads to make you purchase premium), and your own broker’s software.

I usually prefer to sell options, rather than buy them, but that is another post for another time. As usual, this discussion does not constitute advice to buy or sell any security.