What Is Expected Value?
Expected value (EV) is a for❀mula investors use to estimate the likely average return they might earn from an investment over time. They use expected value to estimate the worth of investments, often relative to their risk.
By calculating EVs, investors can choose the scenario most likely to produce the outcome they seek. In statistics and probability analysis, the EV is calculated by multiplying each of the possible outcomes by the likelihood that each outcome will occur and then summing all of those values.
Key Takeaways
- Expected value describes the long-term average level of a random variable based on its probability distribution.
- In investing, the EV of a stock or other investment is an important consideration and is used in scenario analyses.
- Modern portfolio theory uses EV in conjunction with an investment's risk (standard deviation) to come up with optimized portfolios.
- EV can help investors size up whether an investment's risk is worth the potential reward.
Understanding Expected Value
Expected value refers to the anticipated value of an asset in 𒐪the future. The EV of a random variable gives a measure of the center of the distribution of the variable. The EV is essentially the long-term average value of the variable.
Because of the 澳洲幸运5开奖号码历史查询:law of large numbers, the average value of the variable converges to the EV as the number of rep🎉etitions approaches infinity. EV is also known as expectation, the mean, or the first moment.
EV can be calculated for single discrete variables, single continuous v🍸ariables, multiple discrete variables, and multiple continuous variables. For continuous variable situations, integrals must be used.
澳洲幸运5开奖号码历史查询:Scenario analysis is one technique for calculating the EV of an investment opportunity. It uses estimated probabilities with 澳洲幸运5开奖号码历史查询:multivariate models to examine possible outcomes for a proposed investment. Scenario analysis also helps investors determine whether they are taking on an appr🌳opriate level of risk given the likely outcome of the investment.
Important
The difference between expected value and arithmetic mean is th♓at the former involves a distribution of probability, and the latter involves a distribution of occurrence.
Formula for Expected Value
澳洲幸运5开奖号码历史查询: The formula for expected value is:
EV=∑P(Xi)×Xi
澳洲幸运5开奖号码历史查询:where:
- X is a random variable
- Xi are specific values of X
- P(Xi) is the probability of Xi occurring
Thus, the EV of a random variable X is taken as each value of the random variable multiplied by its probability, and each of those products is summe💖d.
Expected Value in Portfolio Construction
Investors need to understand several key factors when they want to construct their investment or 澳洲幸运5开奖号码历史查询:financial portfolios. These include how assets work and their associated risks. Investors should also have a firm grasp on their financial situation, investment goals, and investmꦅent time horizon.
Once they thoroughly understand these factors, investors and their financial advisors can employ EV to build a portfolio that maximizes their retu𒀰rns while minimizing th🌺eir risks.
Example of an Investor Using EV
You ♕can use EV to determine the potential return of an investment🤪 and therefore, which assets to add to your portfolio based on your preference for return.
So, to calculate expected value, first multiply the probability of a positive outcome by the potential return. Say, an investment has a 60% chance of increasing in value by $10,000. The calculation would be: 0.6 x $10,000 = $6,000.
Then, multiply the probability of a negative outcome by the potential loss. For instance, the investment also has a 40% chance of decreasing in value by $5,000. The calculation would be: 0.4 x $5,000 = $2,000.
Finally, subtract the second result from the first: $6,000 - $2,000 = $4,000. That's the EV for this investment.
Next, you may wish to compare two or more investments in which you're interested. Follow the same steps and compare the expected returns. This can help you make selections as you build your portfolio.
Compare EVs for Different Assets
Also, bear in mind that different assets have different EVs. That is, a stock comes with a different expected value (and risk profile) than a bond or an 澳洲幸运5开奖号码历史查询:exchange-traded fund (ETF). It's useful to calculate EVs for the various assets that youᩚᩚᩚᩚᩚᩚᩚᩚᩚ𒀱ᩚᩚᩚ're interested i𒊎n and compare those results.
You can also use EV to adjust your portfolio once it's built. For instance, compare EVs to determine whether selling an underperforming asset with no expectation of a rise in value and replacing it with another with a higher EV makes sense.
Example of Expected Value
To calculate the EV for a single discrete random variable, yo🐽u must multiply each value of t🐲he variable by the probability of that value occurring.
Take, for example, a normal six-sidedꩲ die. Once you roll the die, it has an equal one-sixth probability of landing on the values of either one, two, three, four, five, or six. Given this information, the calculation is:
(61×1)+(61×2)+(61×3)+(61×4)+(61×5)+(61×6)=3.5
If you were to💟 roll a six-sided die an infinite number of times, you would find that the average value equal😼s 3.5.
What Is a Dividend Stock's Expected Value?
The expected value of a stock is estimated as the 澳洲幸运5开奖号码历史查询:net present value (NPV) of all future dividends that the stock pays. If you can estimate the growth rate of the dividends, you can predict how much investors should willingly pay for the stock using a dividend discount model such as the 澳洲幸运5开奖号码历史查询:Gordon growth model (GGM). However, it should𒈔 be noted that this is a different formula from t🍸he statistical expected value presented in this article.
How Do I Find the Expected Value of a Stock That Doesn't Pay Dividends?
For non-dividend stocks, analysts often use a 澳洲幸运5开奖号码历史查询:multiples approach to come up with the expected value. For example. The price-to-earnings (P/E) ratio is often used and compared to industry peers. So, if the tech industry has an average P/E of 25x, a tech stock's EV would be 25 times its earnings per share. Again, this is different than the statistical expected value presented in this article. However, it is another commonly used method for examining a stock's value.
How Is the Expected Value of a Stock Used in Portfolio Theory?
Modern portfolio theory and related models use mean-variance optimization to come up with the best portfolio allocation on a risk-adjusted basis. Risk is measured as the portfolio's standard deviation, and the mean is the expected value (澳洲幸运5开奖号码历史查询:expected return) of the portfolio. This does utilize the concepts presented in this articl👍e.
The Bottom Line
Understanding the con🐠cept of expected value is important for investors. It can aid them in determining the level of return that they might expect from an investment. Expected value and scenario analysis can provide insight into the risk of an investment versus its return and help an investor decide whether or not to include it in their portfolio.