How Options Differ From Buying Shares

Buying shares gives you partial ownership of a company with no end date, while buying an option gives you a contract that expires. The option's value depends on the stock price, the strike price, the time left and the market's expectation of future price swings, so a trade can lose money even when the stock moves the right way.

Key takeaways

A share has no expiration date; an equity option does, and an option that is not in the money at expiration is treated as worthless.
One standard equity option contract usually covers 100 shares, and its premium is quoted per share, so a $2.50 premium costs $250 per contract.
A buyer's loss is capped at the premium, but in the example below that cap is the whole $5,000 at any price at or below $50, while the shares lose 20% at $40.
Option holders do not receive dividends or voting rights unless they exercise and own the shares.
Writing options carries much larger risks than buying them, and a broker must approve an account before it can trade options.

What you own with each choice

A share is an ownership stake with no deadline; its profit or loss follows the stock price from purchase to sale.

According to the Options Industry Council (OIC), an education resource provided by the Options Clearing Corporation (OCC), an equity option is a contract giving its holder the right, but not the obligation, to buy (a call) or sell (a put) shares at a set price, the strike price, on or before an expiration date. After that date the option ceases to exist. The seller, called the writer, is obligated to deliver or buy the shares if the holder exercises.

The same OIC page states that option holders do not enjoy stockholder rights such as voting or regular and special cash dividends, and that a call holder must exercise the option and take the shares to become eligible for them. Dividends still matter: OIC notes that call owners might exercise early to own the stock and receive a dividend, so writers of deep in-the-money calls face a higher chance of early assignment before a sizeable dividend.

Contract terms that shape the risk

Premium, multiplier and breakeven

An option's price, the premium, is quoted per share. The SEC's investor bulletin on options explains that a $2.20 premium on a contract covering 100 shares costs $220, paid up front and non-refundable. The same bulletin shows the breakeven logic for a call: the stock must finish above the strike plus the premium.

Call breakeven at expiration = strike + premium per share
Put breakeven at expiration  = strike - premium per share
Call value at expiration     = max(stock price - strike, 0) x 100 per contract
Put value at expiration      = max(strike - stock price, 0) x 100 per contract

OIC's page on leverage and risk splits a premium into intrinsic value, the amount an option is in the money, and time value, the rest. At-the-money and out-of-the-money options have no intrinsic value, yet they still cost something.

Expiration, weeklies and exercise style

OIC says most monthly equity options expire on the third Friday of the month, moving to the preceding Thursday if that Friday is an exchange holiday, and that many products now have weekly expirations. Cboe's equity LEAPS specifications also give the third Friday. The exact date should be read from the specific contract.

Exercise style also differs. OIC's FAQ says all exchange-traded equity options are American-style, meaning they can be exercised any time on or before expiration, while most index options are European-style and can be exercised only on the expiration date.

A $5,000 example, two ways

Illustrative example (hypothetical numbers, not a forecast). A stock trades at $50. With $5,000, one choice is 100 shares; the other is calls with a $50 strike at a $2.50 premium. Each contract costs $2.50 x 100 = $250, so $5,000 buys 20 contracts, which control 2,000 shares. The table shows the result at expiration only; commissions, fees, taxes and any value before expiration are ignored.

Stock price at expiration	100 shares: P/L	100 shares: return	20 calls: value	20 calls: P/L	20 calls: return
$40.00	-$1,000	-20%	$0	-$5,000	-100%
$45.00	-$500	-10%	$0	-$5,000	-100%
$50.00	$0	0%	$0	-$5,000	-100%
$52.50	+$250	+5%	$5,000	$0	0%
$55.00	+$500	+10%	$10,000	+$5,000	+100%
$60.00	+$1,000	+20%	$20,000	+$15,000	+300%
$70.00	+$2,000	+40%	$40,000	+$35,000	+700%

The shares break even at $50, while the calls break even at $52.50 (strike plus premium). The calls' maximum loss is the $5,000 premium, which happens at any price at or below $50. And because 20 contracts control 20 times as many shares as the 100-share purchase, the calls only beat the shares once the stock passes about $52.63; between $50 and that price the shares do better, and below $52.50 the calls still show a loss.

The loss limit therefore does not mean a small loss. At $45 the shares are down $500 and the calls are down $5,000. OIC warns that leverage can magnify the percentage loss, up to the whole premium. A buyer who wants dollar risk closer to the share purchase could buy fewer contracts: one contract risks $250 (5% of the $5,000) and at $55 is worth $500, a $250 profit or 100% of that premium.

The same sizing can be run in the position size calculator by entering the premium per share as the entry price and $0 as the stop, since the whole premium is at risk; the result in shares divided by 100, rounded down, gives whole contracts. A $5,000 account risking 5% gives $250 / $2.50 = 100 shares, or one contract.

What a protective put costs

A put bought alongside shares works, in OIC's words, as an insurance policy: at the cost of the premium, the owner has the right to sell at the strike price no matter how far the stock falls before expiration. Nothing is guaranteed, because the protection ends at expiration and the premium is spent whatever happens.

Illustrative example (hypothetical). Buy 100 shares at $50 and one put with a $47.50 strike at a $1.20 premium. The premium costs $1.20 x 100 = $120, so the total outlay is $5,120.

Stock price at expiration	Shares only: P/L	Shares plus put: P/L	Shares plus put: return on $5,120
$40.00	-$1,000	-$370	-7.2%
$45.00	-$500	-$370	-7.2%
$50.00	$0	-$120	-2.3%
$55.00	+$500	+$380	+7.4%
$60.00	+$1,000	+$880	+17.2%

The maximum loss is $370: the $250 drop from $50 to $47.50 on 100 shares plus the $120 premium. The breakeven rises from $50 to $51.20. In exchange for the $120, the downside below $47.50 is covered until the put expires, and every upside outcome is $120 lower than with shares alone.

Time, volatility and spreads

Time decay

OIC explains that the longer an option has until expiration, the higher its premium, and that even if nothing else changes, the time value portion decays as time passes. Decay increases rapidly in the last several weeks of an option's life. A sideways stock leaves a share owner where they started but drains an option's time value.

Implied volatility

Implied volatility is the market's estimate of how much the stock may fluctuate over the option's remaining life. OIC's options pricing page says higher volatility estimates generally mean higher premiums for puts and calls alike, most noticeably for at-the-money options. When those estimates fall, premiums tend to fall too, so an option can lose value even when the stock has not moved against the holder.

Liquidity and the bid/ask spread

Option prices come from the best bids and offers of buyers and sellers, as OIC's overview explains. With a bid of $0.40 and an ask of $0.60, buying at the ask and selling straight back at the bid loses $0.20 per share, 40% of the $0.50 midpoint, before the stock moves at all.

Exercise, assignment, splits

A holder can sell the option, let it expire or exercise it. OIC's page on exercising options explains that exercising an American-style option means directing the broker to submit an exercise notice to OCC, before the broker's cut-off time, and that the writer on the other side is assigned. The writer of an American-style option can be assigned at any time before expiration. Once assigned, the writer must carry out the contract.

FINRA's options page separates the two sides: a buyer can lose at most the premium, while the loss on an uncovered call is theoretically unlimited, and sellers also face assignment and margin calls.

Corporate actions change contracts. OIC says contract size, deliverable or strike price may be adjusted for stock splits or mergers. In its FAQ on a 1-for-10 reverse split, the strike stays the same, the multiplier stays 100 and the deliverable becomes 10 shares, so what the contract delivers changes even though the strike does not.

Frequently asked questions

Who can trade options, and what must a broker do first?

FINRA says a brokerage firm must approve an account for a specific level of options trading before any trading. Under FINRA Rule 2360, the firm has to use due diligence to learn the customer's financial situation, investment objectives and options experience, and must deliver the current Characteristics and Risks of Standardized Options disclosure document at or before approval. The edition checked for this article, the June 2024 ODD, warns that an option holder "runs the risk of losing the entire amount paid for the option in a relatively short period of time." OIC's ODD Quick Guide is a study aid and not a substitute for the document.

What happens to an in-the-money option at expiration if nothing is done?

FINRA's options page says in-the-money equity options are generally exercised automatically at expiration. OIC adds that each brokerage firm has its own procedure, and that OCC uses a $.01 threshold for its clearing members while a firm may set a different one. A holder can always instruct the broker to exercise or not.

How are option gains and losses taxed?

IRS Publication 550 says the cost of a call or put is not deductible when bought. If the holder sells the option or lets it expire, the result is a short-term or long-term capital gain or loss depending on the holding period. If a call is exercised, its cost is added to the basis of the stock; if a put is exercised, the cost reduces the amount realized on the shares. Buying a put is generally treated as a short sale, so for stock held one year or less when the put is bought, a gain on the put is short-term, and the stock's holding period starts over on the earliest of the date the stock is sold or the put is exercised, sold or expires. The edition checked here is Publication 550 for 2025; special rules apply to nonequity options such as many index options.

Are weekly options different from monthly ones?

Weekly options are separate series with their own expiration dates. OIC's weekly options FAQ says they are listed on a Thursday and in most cases expire the following Friday, and that equity and ETF weeklies are physically settled and American-style.

Why do some sources say options expire on a Saturday?

That was the old convention. Standard monthly options used to expire on the Saturday after the third Friday, so the Friday before it was the last business day for exercise decisions. A 2014 FINRA rule filing describes OCC's change of the expiration date to the third Friday for standard contracts expiring after February 1, 2015. The SEC's options bulletin still contains the Saturday wording in its terminology section, while its worked examples use the third Friday.

Checklist before a first trade

Read the current options disclosure document that the broker supplies and confirm what level of options trading the account is approved for.
Write down the contract in full: underlying stock, expiration date, strike, call or put, and exercise style.
Calculate the breakeven at expiration (strike plus or minus premium) and the total premium in dollars, then compare that dollar amount with the account size.
Check the bid/ask spread as a share of the premium.
Decide in advance whether to sell, exercise or let the contract expire, and what the broker's exercise cut-off and automatic-exercise rules are.