What Is a Call Option?

定义

Call options are financial contracts that give the option buyer the right, but not the obligation, to buy a stock, bond, commodity or other asset or instrument at a specified price within a specific time period. The stock, bond, or commodity is called the underlying asset. A call buyer profits when the underlying asset increases in price.

看涨期权是一种金融合约，赋予期权买方在特定时间段内以指定价格购买股票、债券、商品或其他资产或工具的权利，但没有义务。股票、债券或商品称为标的资产。当标的资产价格上涨时，看涨期权买方获利。

A call option may be contrasted with a put, which gives the holder the right to sell the underlying asset at a specified price on or before expiration.

看涨期权可能与看跌期权形成对比，看跌期权赋予持有人在到期日或到期前以指定价格出售标的资产的权利。

KEY TAKEAWAYS

要点

·A call is an option contract giving the owner the right, but not the obligation, to buy a specified amount of an underlying security at a specified price within a specified time.

·看涨期权是一种期权合约，赋予所有者在指定时间内以指定价格购买指定数量的基础证券的权利，但没有义务。

·The specified price is known as the strike price and the specified time during which a sale is made is its expiration or time to maturity.

·指定价格被称为行使价，销售的指定时间是其到期时间。

·Call options may be purchased for speculation, or sold for income purposes. They may also be combined for use in spread or combination strategies.

·看涨期权可能是为了投机而购买，也可能是为了收益而出售。它们也可以组合用于传播或组合策略。

The Basics of Call Options

构成要素

For options on stocks, call options give the holder the right to buy 100 shares of a company at a specific price, known as the strike price, up until a specified date, known as the expiration date.

对于股票期权，看涨期权赋予持有人以指定价格（称为行使价）购买 100 股公司股票的权利，直至特定日期（称为到期日）。

For example, a single call option contract may give a holder the right to buy 100 shares of Apple stock at $100 up until the expiry date in three months. There are many expiration dates and strike prices for traders to choose from. As the value of Apple stock goes up, the price of the option contract goes up, and vice versa. The call option buyer may hold the contract until the expiration date, at which point they can take delivery of the 100 shares of stock or sell the options contract at any point before the expiration date at the market price of the contract at that time.

例如，单一看涨期权合约可能赋予持有人以 100 美元购买 100 股苹果股票的权利，直至三个月到期日。有多个到期日和行使价供交易者选择。随着苹果股票价值的上涨，期权合约的价格也会上涨，反之亦然。看涨期权买方可以持有合约至到期日，此时他们可以在到期日之前的任何时间以合约当时的市场价格交割100股股票或卖出期权合约。

The market price of the call option is called the premium. It is the price paid for the rights that the call option provides. If at expiry the underlying asset is below the strike price, the call buyer loses the premium paid. This is the maximum loss.

看涨期权的市场价格称为溢价。其为看涨期权提供的权利而支付的价格。如果到期时标的资产低于行使价，看涨期权买方将失去已支付的溢价，将会是最大的损失。

If the underlying's price is above the strike price at expiry, the profit is the current stock price, minus the strike price and the premium. This is then multiplied by how many shares the option buyer controls.

如果标的价格在到期时高于行使价，则利润为当前股票价格减去行使价和溢价。然后乘以期权买方控制的股份数量。

For example, if Apple is trading at $110 at expiry, the strike price is $100, and the options cost the buyer $2, the profit is $110 - ($100 +$2) = $8. If the buyer bought one contract that equates to $800 ($8 x 100 shares), or $1,600 if they bought two contracts ($8 x 200). If at expiry Apple is below $100, then the option buyer loses $200 ($2 x 100 shares) for each contract they bought.

例如，如果苹果在到期时的交易价格为 110 美元，行使价为 100 美元，而期权成本为买方 2 美元，则利润为 110 美元 － (100 美元 + 2 美元) = 8 美元。如果买方购买了一份相当于 800 美元（8 x 100 股）的合约，或者如果他们购买了两份合约（8 x 200 美元），则为 1,600 美元。如果到期时苹果股价低于 100 美元，那么期权买方每购买一份合约就会损失 200 美元（2 美元 x 100 股）。

Important: Call options are often used for three primary purposes. These are income generation, speculation, and tax management.

重点：看涨期权通常用于三个主要目的：创收、投机和税收管理。

There are several factors to keep in mind when it comes to selling call options. Be sure you fully understand an option contract's value and profitability when considering a trade, or else you risk the stock rallying too high.

在出售看涨期权时，有几个因素需要牢记。在考虑交易时，一定要充分了解期权合约的价值和盈利能力，否则你就要冒股票反弹过高的风险

Covered Calls for Income

看涨期权与创收

Some investors use call options to generate income through a covered call strategy. This strategy involves owning an underlying stock while at the same time writing a call option, or giving someone else the right to buy your stock. The investor collects the option premium and hopes the option expires worthless (below strike price). This strategy generates additional income for the investor but can also limit profit potential if the underlying stock price rises sharply.

某些投资者使用看涨期权通过有保障的看涨策略产生收益。该策略涉及在持有标的股票的同时沽出看涨期权，或给其他人购买您股票的权利。投资者收取期权溢价并希望期权到期时毫无价值（低于行使价）。该策略为投资者带来额外收入，但如果标的股票价格大幅上涨，也会限制潜在的利润。

Covered calls work because if the stock rises above the strike price, the option buyer will exercise their right to buy the stock at the lower strike price. This means the option writer doesn't profit on the stock's movement above the strike price. The options writer's maximum profit on the option is the premium received.

备兑看涨期权之所以起作用，是因为如果股票涨到行使价以上，期权买方将行使权利以较低的行使价买入股票。即期权卖方不会从股票高于行使价的波动中获利。期权卖方在期权上的最大利润是所收到的溢价。

Using Options for Speculation

看涨期权与投机

Options contracts give buyers the opportunity to obtain significant exposure to a stock for a relatively small price. Used in isolation, they can provide significant gains if a stock rises. But they can also result in a 100% loss of premium, if the call option expires worthless due to the underlying stock price failing to move above the strike price. The benefit of buying call options is that risk is always capped at the premium paid for the option.

期权合约让买方有机会以相对较低的价格获得大量股票。如果单独使用，其可以在股票上涨时提供显著收益。但是，如果由于标的股票价格未能高于行使价而使看涨期权到期毫无价值，也可能导致溢价损失100%。购买看涨期权的好处是，风险总是以期权的溢价为上限。

Investors may also buy and sell different call options simultaneously, creating a call spread. These will cap both the potential profit and loss from the strategy, but are more cost-effective in some cases than a single call option since the premium collected from one option's sale offsets the premium paid for the other.

投资者也可以同时买卖不同的看涨期权，从而产生看涨期权价差。其将限制策略的潜在利润和损失，但在某些情况下比单一看涨期权更具成本效益，因为从一个期权的销售中收取的溢价抵消了为另一个支付的溢价。

Using Options for Tax Management

看涨期权与税收管理

Investors sometimes use options to change portfolio allocations without actually buying or selling the underlying security.

投资者有时会使用看涨期权来改变投资组合分配，而无需实际买卖标的证券。

For example, an investor may own 100 shares of XYZ stock and may be liable for a large unrealized capital gain. Not wanting to trigger a taxable event, shareholders may use options to reduce the exposure to the underlying security without actually selling it. While gains from call and put options are also taxable, their treatment by the IRS is more complex because of the multiple types and varieties of options. In the case above, the only cost to the shareholder for engaging in this strategy is the cost of the options contract itself.

例如，投资者可能拥有 100 股 XYZ 股票，并且可能要对大量未实现的资本收益负责。由于不想触发应税事件，股东可以使用看涨期权来降低基础证券的敞口，而无需实际出售。虽然看涨期权和看跌期权的收益也应纳税，但由于期权种类繁多，美国国税局对它们的处理更为复杂。在上述情况下，股东参与此策略的唯一成本是期权合约本身的成本。

Real World Example of a Call Option

看涨期权实例

Suppose that Microsoft shares are trading at $108 per share. You own 100 shares of the stock and want to generate an income above and beyond the stock's dividend. You also believe that shares are unlikely to rise above $115.00 per share over the next month.

假设微软股票的交易价格为每股 108 美元。您拥有 100 股股票，并希望获得高于股票股息的收入。您还认为股价在下个月不太可能升至每股 115.00 美元以上。

You take a look at the call options for the following month and see that there's a 115.00 call trading at $0.37 per contract. So, you sell one call option and collect the $37 premium ($0.37 x 100 shares), representing a roughly four percent annualized income.

您查看下个月的看涨期权，看到有 115.00 看涨期权交易价格为每份合约 0.37 美元。 因此，您卖出一个看涨期权并收取 37 美元的溢价（0.37 美元 x 100 股），相当于年化收入的大约 4%。

If the stock rises above $115.00, the option buyer will exercise the option and you will have to deliver the 100 shares of stock at $115.00 per share. You still generated a profit of $7.00 per share, but you will have missed out on any upside above $115.00. If the stock doesn't rise above $115.00, you keep the shares and the $37 in premium income.

如果股票上涨至 115.00 美元以上，期权买方将行使期权，您必须以每股 115.00 美元的价格交付 100 股股票。您仍然获得了每股 7.00 美元的利润，但您将错过任何高于 115.00 美元的上涨空间。如果股票没有升至 115.00 美元以上，您将保留股票和 37 美元的保费收入。

英文来源：https://www.investopedia.com/terms/c/calloption.asp