Wow! We had a great turnout here in Las Vegas this week, and I want to thank all of you who came to see us. Your wonderful support and kind expressions of praise for VectorVest are appreciated deeply. I also want to send a warm welcome to our Las Vegas User Group, coming very soon. If anyone has a suggestion as to where it can meet, please email Amy at
amyo@vectorvest.com. Thank you for attending The Las Vegas Money Show.
RISK, REWARD AND PROBABILITY.
Last week I wrote about a guy who lost $500,000 on a question a fifth grader could answer. I called him a fool because he had no idea what his chances were of winning. As investors, how can we assess our chances of winning?
Statistical theory tells us that stock prices are just as likely to go down as they are to go up. So our chances of winning, without any other considerations, are 50%. OK, but this answer says nothing in regard to risk and reward. The character I referred to last week, at least knew he could win $1,000,000. So how can we determine the probable risk and reward of a given stock purchase?
This is where volatility comes into the picture. Everyone knows that risk increases with higher volatility, but it's hardly ever mentioned that reward also increases with higher volatility. Risk and reward change to the same degree given a normal distribution of statistical probability. One must specify a time period, however, to determine the probability of the occurrence of a given price change. And the Option Pricing Model is the perfect tool for making this assessment. So let's see how it's done.
Please access Stock Viewer and set the Drop Down Calendar to 05/17/07. Find First AmerCorp., FAF. (I picked this stock because it closed at $50.01 per share.) Right click anywhere on the FAF row and select "Calculate Option Price." The Option Pricing Model pops up, complete with the results of its computation. At the top of the screen, note that the Statistical Volatility for the last 50 trading days was 17.43%. This volatility is pretty low and suggests that there would be low risk in buying this stock. Unfortunately, the reward would also be low. The item labeled "Delta" on the Call side of the screen says that there was only a 4% chance of this stock closing at or above $55.00 by June 15, 2007.
If you click on the little box labeled "Use Implied Volatility," enter 100 in the box labeled "Implied Volatility" and click on the "Calculate" button, you'll see that the Delta or probability of FAF closing at or above $55.00 by June 15, 2007 increased to 43%. This is much better, but the chances of the stock falling to or below $45.00 have also increased to 43%. Pretty neat, huh? Yes, if that were all there was to picking stocks.
Let's set Stock Viewer back to 12/14/06 and find FAF again. FAF closed at $41.06 on that day. The Option Pricing Model said that there was only a 3% chance of it closing at or above $50.00 by the end of trading on March 16, 2007. It did, however, on 03/07/07. Does this mean that the Option Pricing Model is no good? Not really. It just means that there is a whole lot more to picking stocks than a cold, hard statistical assessment of Risk, Reward and Probability.