Can You Calculate Expected Value of an Options Trade Yourself?

It’s tempting to dive into options trading through your brokerage app and chase those juicy weekly options premiums. The apps make it look easy—click a button, place an order, watch the confetti fly. But beneath the surface, there’s serious math that too often gets ignored. The key to any sensible trade—or any investment decision at all—is expected value. It’s the real dividing line between winning players and frequent losers.

In this post, we’re going to walk through the basics of expected value investing, unpack options pricing basics, and show why probability in trading matters more than you think. By the end, you’ll see that yes, you can calculate the expected value (EV) of an options trade yourself—but only if you know what to look for and don’t ignore the hidden costs and risks.

What Is Expected Value, Anyway?

Expected value is a statistical concept that measures the average result you can expect from a random event over the long run. It’s key in gambling, investing, and everyday decision-making. Simply put:

Expected Value (EV) = (Probability of each outcome) × (Payoff of each outcome), summed over all outcomes.

In casino games, for example, the EV is usually negative for players because the house edge ensures the casino wins over time. In investments, positive EV means your average payoff exceeds your costs.

Why “The Sign In Front of The Number” Matters

When talking EV, I always stress: pay attention to the sign in front of the number. A positive EV means your rewards exceed your risks on average. Negative means you’re expected to lose money over time—even if you feel lucky on any given trade. Ignoring the sign turns savvy trading into blind gambling.

Why Expected Value Matters in Equity Ownership vs Options Trading

Broad equity ownership, like buying and holding index funds, generally has a positive expected value historically. Over decades, equities tend to grow wealth because economies expand. That positive EV is clear, transparent, and supported by published returns.

By contrast, options trading—especially buying weekly options through brokerage apps—can have a negative EV overall. Many retail traders don’t realize how fast decay, fees, and assignment risks chip away at their odds.

Options Pricing Basics You Need to Understand

Before calculating EV, let’s quickly cover the core mechanics behind options pricing:

Theta Decay: This measures the rate at which an option's time value erodes as expiration approaches. Weekly options have a fast theta decay, making it a race against time.
Assignment Risk: If you’re selling options, there’s a risk you'll be assigned and must fulfill the underlying obligation, often at a loss.
Bid-Ask Spread: The difference between the price you buy at and the price you can sell at. Wide spreads increase your cost.
Commission: Fees charged by the brokerage per trade. Even low commissions add up over many trades.

If your brokerage app hides or glosses over these costs, you’re not seeing the true EV of your trade. Transparency matters.

Step-By-Step: How to Calculate Expected Value of an Options Trade Yourself

Here’s a simplified but practical approach to estimate the EV for a single options trade. I recommend working in a spreadsheet to get precise numbers.

Define Possible Outcomes: Determine all your outcomes. For example, if you buy a weekly call, it either expires worthless, or it finishes in-the-money.
Estimate Probabilities: Use option-implied probabilities or your own scenario analysis. For weekly options, implied probability can be extracted from options prices.
Calculate Payoffs: For each outcome, calculate the net payoff after subtracting your cost, commissions, and adjusting for the bid-ask spread.
Sum Weighted Outcomes: Multiply each payoff by its probability and add them to get the expected value.
Interpret the Result: Is EV positive or negative? Remember the sign.

Simple Example: Buying a Weekly Call Option

Outcome Probability Payoff Weighted Value (Probability × Payoff) Expires worthless (out of the money) 80% –$200 (premium paid + fees + spread) 0.80 × (–$200) = –$160 Finishes ITM by $300 20% $300 – $200 = $100 net profit 0.20 × $100 = $20

Expected Value = –$160 + $20 = –$140

Negative EV. Over many trades, you expect to lose $140 on average.

Why Time Horizon and Law of Large Numbers Matter

EV is an average result over many repetitions. Individual trades follow randomness—you might win big once or twice and think you’re a genius. But the law of large numbers says your average results will converge on EV only after many trades.

In options trading, short expiration weekly options have tiny windows for success and steep time decay working against you. If your EV is negative, no amount of “stopping early” or “gut https://thinkaora.com/luck-is-not-a-plan-where-investing-and-games-of-chance-actually-differ/ feeling” will save you in the long run.

A Warning Against Gamified Trading Apps

Many apps flash confetti and leaderboards to make you feel good about small wins. They hide the small, constant losses eating away at your account and never publish true metrics like return to player (RTP) or expected value. Remember, the house (the brokerage and market makers) sets the odds. Without transparency, you’re playing a rigged game.

Keep These Tips in Mind

Always calculate or at least estimate EV before trading any option—don’t trade on vibes or hype.
Factor in every cost: commissions, bid-ask spreads, and the risk of assignment.
Use tools that display implied volatility and probabilities—not just the premium prices.
Understand that expected value guides long-term success—not quick wins.

Summary

In retail options trading, expected value is the fundamental metric that separates smart investors from gamblers. While calculating it yourself might seem daunting at first, understanding the formula and accounting for options mechanics like theta decay, assignment risk, spreads, and commissions is essential to avoid hidden losses.

Remember the difference between broad equity ownership's positive EV and the negative EV traps in many weekly option trades offered by slick brokerage apps. Without transparency on costs and probabilities, it’s easy to lose more than you realize.

By focusing on the sign in front of the number, respecting the law of large numbers, and insisting on full disclosure of fees and probabilities, you can make informed choices or decide the game isn't worth playing.

Want to master expected value investing? Start with your options trades. Your bankroll will thank you.