We recently discussed option prices in the marketplace, and how they depend on several factors, in addition to supply and demand. To allow you to better understand how options are priced – why they rise and fall – let’s look at each of these factors in closer detail.
View Key Differences Between Options and Stocks, Part 1.
1. Price of the underlying
If you own a call option, you have the right to buy stock at a specific price (strike price). For example, if you own one Nov 40 call, you can buy 100 shares at $40 per share. Wouldn’t you pay more to own that call if the stock is $39 than if it’s $35? Would you pay even more if the stock price is $43? I hope you replied ‘yes.’ That’s why calls are worth more as the stock rises.
2. Option type
A call gives you the right to buy shares and a put gives you the right to sell shares. Thus you cannot expect put and call prices to move in tandem. When the stock moves higher, call options increase in value and put options decrease in value.
3. Time to Expiration
When you own an option, you want to see the stock move higher (call option) or lower (put option). The more time that remains before an option expires, the greater the chance that a favorable more will occur. Thus, more time makes all options more valuable. It’s true that more time allows the stock to make an unfavorable move, but that’s not the significant factor in determining a price of an option. It’s the potential payoff, and the probability of receiving that payoff, that determines an option’s value.
4. Interest Rates
Call options can be used as an alternative to owning stock. When you buy stock, you must use cash, and that cash could be invested to earn interest. Thus, the more interest you earn on your cash, the more you should be willing to pay for a call option. This is not a significant factor in determining an option’s value.
5. Strike Price
When you buy stock, you want to pay the lowest possible price. Thus, the right to buy stock at $25 per share is more valuable than the right to buy stock at $30 per share. For that reason, call options increase in value as the strike price decreases.
When selling stock, you want to receive the highest possible price. Thus, it’s more valuable to own the right to sell shares at $60 than the right to sell shares at $55. Puts are worth more as the strike price increases.
When a stock pays a dividend, its price declines by the amount of that dividend. That occurs when the stock ‘goes ex-dividend’ (the buyer is not entitled to receive the dividend). The higher the dividend, the more the price declines. Because a lower stock price is not good for the call owner, as the dividend increases, the value of a call option decreases. Similarly, the value of a put option increases.
These options do not suddenly change price when the stock goes ex-dividend. The model (modified Black-Scholes) that determines the fair value of an option ‘knows’ that the stock has a dividend in its future, and the effect of that dividend is already priced into the option when you buy or sell it.
When you own an option, you want the stock price to change by a large amount because when the stock moves far beyond the strike, the value of your option increases. When stocks are not very volatile and undergo daily price changes of a few pennies, a big move is unlikely. But when the stock price frequently changes by 5% in a single day, a few of those moves in the same direction can provide a handsome profit. Thus, the options of more volatile stocks are worth a great deal more than options of non-volatile stocks. Example.
Further Reading, Options:
- The Key Differences Between Options and Stocks
- New investors, What is an option?
- 6 Great Options Strategies for new investors
- 7 Reasons Investors Trade Options
- 9 Options Terms every investor should know
- 12 Intermediate Option Terms to know
View all of Mark’s Posts.