How to select an option strike price?

How to select an option strike price?
Richard Ho Invest, Personal Invest, Personal

Richard Ho, Senior Manager—Equity derivatives at Montréal exchange, will shed light on a question many do-it yourself investors ask themselves.

While talking to a friend recently, the conversation turned to the markets and he asked me, “How do you know which strike price to use?” It was a legitimate question. As a matter of fact, many investors I meet ask me the same thing: How do you select a strike price? So, I answered him with another question: “How do you use your GPS?” He told me to stop joking around, but I was serious. Selecting an option strike price is the same thing as using a GPS: you need to know where you are going. If you do not know your destination, there is no point to having a GPS, just like options. Now I will share with you what I told him that day about option strike prices and GPSs.

For simplicity’s sake, I will stick with a call option. For those of you who may not be familiar with options, a call option gives the owner the right (but not the obligation) to buy the underlying stock at a given price (called a strike price). This call option gives the holder the right to buy the stock at any time until the option expires.

When you turn on a GPS, you must tell it where you want to go and then it will give you the optimal route. The same thing is true of options (this applies to calls and puts): you need to have an expected target price. The expected target price corresponds to the price you forecast a stock will reach in the future. If you are new to target prices, you can find them in analyst reports or by using the technical analysis tools provided by your online broker.
Let’s go back in time so I can show you an actual example using Teck Resources Limited (TECK. B). In the candlestick chart below, on a few occasions (between December 2016 and April 2017), the share price climbed up into the low-mid 30s and then pulled back.

On June 21, 2017, the stock closed at $20.37. If we had assumed that it would rally back to $30, we could have expressed this view by purchasing a call option (expiring on August 18, 2017).

How to select an option strike price?

The expected target price of $30 is equivalent to the final destination that we enter into a GPS. Whether or not we get there is another story. As long as we have an expected target price, we can reverse engineer the route in order to find the optimal strike price that will give us the greatest return.

Expected target price: $30

Return formula:

(Expected target price – Strike price – Price paid for the call option)
Price paid for the call option


Simply apply the return formula to all the strike prices on the call options expiring on August 18, 2017. The strike price that yields the greatest expected return (in this case, $27) will be the one to use for this trade.

How to select an option strike price?

Upon expiry of the options (on August 18, 2017), Teck Resources Limited had rallied to $29.34. Anyone who bought the $27 call options for $0.14 would have made a 1,571% return. And if the stock hadn’t risen as anticipated, the maximum loss would have been $0.14 (or $14 per option contract).

Now that you know a little more on how to select an option strike price, may the best trades be with you.


National Bank Direct Brokerage (“NBDB”) is a division of and a trademark used by National Bank Financial Inc. (“NBF ‘) for its order-execution services. National Bank Direct Brokerage offers no advice and makes no investment recommendations. The client is solely responsible for the financial consequences of his or her investment decisions. Member of the Canadian Investor Protection Fund.

Edited on 13 April 2018

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