A stock can rise 10% while the money in its call falls

When you expect strong earnings, buying calls instead of shares can look like a way to win more. But getting the direction right and recovering the price paid for that right are different bets. In an equal-budget model of two fictional stocks, A rose 2% and its cash-plus-call value reached about $15,226; B rose 10% and left about $7,538.

Public discussions on October 12–13 compared the option reward from small bank-stock moves with larger chip-stock moves; readers also questioned an earnings call’s expiry and buying both directions. Move versus IV debate, earnings-call expiry question, both-directions question. The figures below are hypothetical calculations built to answer that money question.

You bought a right, with its own price

A call lets its owner purchase shares for a specified exercise price. Standard US equity contracts usually cover 100 shares, while premiums are quoted per share. Adjusted contracts can differ, so check the exact multiplier and expiry. OIC option basics.

After purchase, the stock, time remaining and priced-in volatility can all change. OIC explains that a stock rise lifts a call with other inputs held constant, but changes such as lower volatility after an event can overwhelm that benefit. OIC price behavior. The question therefore extends from how far the stock might rise to how much you paid to participate.

Two fictional calls, the same $10,000

Each fictional stock starts at $100. Both calls have a $105 strike and 30 calendar days left. Initial IV is assumed to be 25% for A and 90% for B. One day later, A is $102 and B is $110, with 29 days left. A’s IV stays 25%; B’s is assumed to fall to 25%.

IV is the annualized volatility reflected in an option price. OIC volatility.

We compare Black–Scholes values for non-dividend-paying, European-style calls exercisable only at expiry. Interest rates and cash interest are 0%, a year is 365 days and the assumed multiplier is 100. Main-case trading costs, tax and KRW conversion are zero. Early exercise and delivery procedures for actual US equity options are outside this simple model. Actual premiums come from market quotes. OIC model and market price.

Money amounts are USD; call prices are theoretical values per underlying share. Calculations use full precision before display rounding and only whole contracts affordable within $10,000. Money left = unspent cash + contracts × 100 × day 1 call value. The total combines cash with the marked value of the right; a sale uses the actual fill and costs.

The call price changes are +52.42% for A and -24.99% for B. Including unspent cash, the $10,000 budget changes by +52.26% and -24.62%. Option-price and whole-budget returns use different denominators. Buying 100 shares for the same money would leave $10,200 in A or $11,000 in B. The calls cover 9,200 and 1,200 underlying shares, so equal starting cash does not give equal share exposure or equal risk.

Change B’s inputs one at a time

A and B differ in both stock movement and IV. Keep the same B contract and change time, then the stock, then IV while holding the other inputs fixed. This shows where a correct directional call can still fail to recover its purchase price.

The last two rows both have a $110 stock and 29 days remaining. Changing only IV from 90% to 25% lowers the call value from 13.5314 to 6.1566. This is a controlled model comparison. Changing the time→stock→IV order can alter individual differences because the inputs interact; those steps are not an attribution of actual market causes.

A bigger move or persistent IV reverses the choice

Keep B’s original premium, 12 contracts and unspent cash unchanged, and vary only the day 1 conditions. IV need not fall to 25% after an announcement. A larger rally or persistent volatility belongs in the money comparison too.

With the same 10% stock rise and IV still 90%, B reaches about $16,388, above A’s $15,226. Even at 25% IV, a 20% stock rise leaves about $18,256. There are clear conditions in which the call buyer wins. These comparisons give no rule to buy low-IV options or sell options just because IV is high.

Fix B at $110 with 29 days left: IV of about 44.21% makes its value equal the initial premium. Fix IV at 25% and 29 days: a stock price around $112.55 is that boundary. These are zero-cost model conditions, not forecasts of future IV or share prices.

Today’s mark and the expiry reward differ

A’s reward also has a deadline. If its stock remains $102 at expiry, below the $105 strike, the call’s terminal value is zero; only about $31 of original unspent cash remains. If B expires at $110, its right has $5 of economic value per share and cash-plus-value totals about $6,150. B’s zero-cost terminal break-even is 105 + the initial premium, about $113.21. It differs from the $112.55 boundary before expiry.

The terminal value here is the right’s economic payoff, max(stock−strike, 0). A contract delivering shares also requires attention to exercise funding and the broker’s expiry handling. Taking delivery of the shares covered by B’s 12 contracts at $105 means 12 × 100 × 105 = $126,000 of purchase payments. The $10,000 budget above is not an account funded for that delivery.

Multiplying today’s one-day theta by several days also fails to give an exact future loss along that changing path. OIC theta.

Buying both directions has a price too. A call plus a put at the same fictional B $105 strike costs 21.4164 per underlying share. At stock 110, 29 days and 25% IV, the combined value is 7.3131. Paying for both rights does not create free insurance against post-event repricing.

Check the entry price and the money at exit

Costs can take a larger bite out of a cheaper right. In a separate assumption of $0.05 per underlying share in combined fees and quote friction at entry, and again at exit ($5 per 100-share contract on each side), A’s affordable contracts fall from 92 to 88 and total cash after selling becomes about $14,119. B keeps 12 contracts and about $7,418. This is hypothetical cost sensitivity, not a broker’s tariff; entry size is recalculated with costs included.

For an earnings call, line up the exact strike, expiry, multiplier, purchase ask, sale bid and priced-in IV of the same contract. Your decision changes with the money left under different IV even if the anticipated share price arrives, and with recovery that comes after the deadline. After the actual announcement, matching the same contract’s quotes and IV lets you compare how much of the expectation paid for is still available.

Turning a marked right into cash leads to the difference between a buy signal and an actual fill. If selling options for income appeals to you, monthly distributions versus total money continues the question of cash collected and assets remaining.