A call option, often simply labeled a "call", is a financial contract between two parties, the buyer and the seller of this type of option.[1] The buyer of the call option has the right, but not the obligation, to buy an agreed quantity of a particular commodity or financial instrument (the underlying) from the seller of the option at a certain time (the expiration date) for a certain price (the strike price). The seller (or "writer") is obligated to sell the commodity or financial instrument to the buyer if the buyer so decides. The buyer pays a fee (called a premium) for this right.
When you buy a call option, you are buying the right to buy a stock at the strike price, regardless of the stock price in the future before the expiration date. Conversely, you can short or "write" the call option, giving the buyer the right to buy that stock from you anytime before the option expires. To compensate you for that risk taken, the buyer pays you a premium, also known as the price of the call. The seller of the call is said to have shorted the call option, and keeps the premium (the amount the buyer pays to buy the option) whether or not the buyer ever exercises the option.
For example, if a stock trades at $50 right now and you buy its call option with a $50 strike price, you have the right to purchase that stock for $50 regardless of the current stock price as long as it has not expired. Even if the stock rises to $100, you still have the right to buy that stock for $50 as long as the call option has not expired. Since the payoff of purchased call options increases as the stock price rises, buying call options is considered bullish. When the price of the underlying instrument surpasses the strike price, the option is said to be "in the money". On the other hand, If the stock falls to below $50, the buyer will never exercise the option, since he would have to pay $50 per share when he can buy the same stock for less. If this occurs, the option expires worthless and the option seller keeps the premium as profit. Since the payoff for sold (or written) call options increases as the stock price falls, selling call options is considered bearish.
Call options can be purchased on many financial instruments other than stock in a corporation. Options can be purchased on futures or interest rates, for example (see interest rate cap), and on commodities like gold or crude oil. A tradeable call option should not be confused with either Incentive stock options or with a warrant. An incentive stock option, the option to buy stock in a particular company, is a right granted by a corporation to a particular person (typically executives) to purchase treasury stock. When an incentive stock option is exercised, new shares are issued. Incentive options are not traded on the open market. In contrast, when a call option is exercised, the underlying asset is transferred from one owner to another.
In finance, a put or put option is a stock market device which gives the owner of a put the right, but not the obligation, to sell an asset (the underlying), at a specified price (the strike), by a predetermined date (the expiry or maturity) to a given party (the seller of the put). The purchase of a put option is interpreted as a negative sentiment about the future value of the underlying.[1] Put options are most commonly used in the stock market to protect against the decline of the price of a stock below a specified price. If the price of the stock declines below the specified price of the put option, the owner/buyer of the put has the right, but not the obligation, to sell the asset at the specified price, while the seller of the put has the obligation to purchase the asset at the strike price if the owner uses the right to do so (the owner/buyer is said to exercise the put or put option). In this way the buyer of the put will receive at least the strike price specified, even if the asset is currently worthless.
If the strike is K, and at time t the value of the underlying is S(t), then in an American option the buyer can exercise the put for a payout of K-S(t) any time until the option's maturity time T. The put yields a positive return only if the security price falls below the strike when the option is exercised. A European option can only be exercised at time T rather than any time until T, and a Bermudan option can be exercised only on specific dates listed in the terms of the contract. If the option is not exercised by maturity, it expires worthless. (Note that the buyer will not exercise the option at an allowable date if the price of the underlying is greater than K.)
The most obvious use of a put is as a type of insurance. In the protective put strategy, the investor buys enough puts to cover his holdings of the underlying so that if a drastic downward movement of the underlying's price occurs, he has the option to sell the holdings at the strike price. Another use is for speculation: an investor can take a short position in the underlying stock without trading in it directly.
Puts may also be combined with other derivatives as part of more complex investment strategies, and in particular, may be useful for hedging. Note that by put-call parity, a European put can be replaced by buying the appropriate call option and selling an appropriate forward contract.
A naked put, also called an uncovered put, is a put option whose writer (the seller) does not have a position in the underlying stock or other instrument. This strategy is best used by investors who want to accumulate a position in the underlying stock, but only if the price is low enough. If the buyer fails to exercise the options, then the writer keeps the option premium as a "gift" for playing the game.
If the underlying stock's market price is below the option's strike price when expiration arrives, the option owner (buyer) can exercise the put option, forcing the writer to buy the underlying stock at the strike price. That allows the exerciser (buyer) to profit from the difference between the stock's market price and the option's strike price. But if the stock's market price is above the option's strike price at the end of expiration day, the option expires worthless, and the owner's loss is limited to the premium (fee) paid for it (the writer's profit).
The seller's potential loss on a naked put can be substantial. If the stock falls all the way to zero (bankruptcy), his loss is equal to the strike price (at which he must buy the stock to cover the option) minus the premium received. The potential upside is the premium received when selling the option: if the stock price is above the strike price at expiration, the option seller keeps the premium, and the option expires worthless. During the option's lifetime, if the stock moves lower, the option's premium may increase (depending on how far the stock falls and how much time passes). If it does, it becomes more costly to close the position (repurchase the put, sold earlier), resulting in a loss. If the stock price completely collapses before the put position is closed, the put writer potentially can face catastrophic loss. In order to protect the put buyer from default, the put writer is required to post margin. The put buyer does not need to post margin because the buyer would not exercise the option if it had a negative payoff.