什么是看跌期权？

What is a put option?

A put option (long put) refers to the purchase of a put option, usually in anticipation of a decline in the price of the underlying asset. The "long" here does not refer to the length of time before expiration, but rather refers to the way the trader operates in the hope of selling the option at a higher price in the future.

Traders may purchase put options for speculative purposes, betting that the price of the underlying asset will fall, which will increase the value of the put option. Put options can also be used to hedge a long position in the underlying asset. If the price of the underlying asset falls, the put option rises in value, helping to offset losses in the underlying asset.

Key Points

• A put option is when someone buys a put option. This in itself is a strategy to short the market.
• Investors buy put options if they believe the price of a security will fall.
• Investors may choose to buy put options to speculate on falling prices or to hedge against downside risk in a portfolio. -Use a put option strategy, thus limiting downside risk.

Understanding put options

A put option has a strike price, which is the price at which the buyer of the put option can sell the underlying asset. Assume the underlying asset is a stock and the option has a strike price of $50. This means that the put option gives the trader the right to sell the stock at$50, even if the stock price drops to $20. On the other hand, if the stock rises and remains above$50, the option will become worthless because there is no need to sell the stock at $50 when the stock is trading at$60.

If a trader wishes to exercise the right to sell the underlying asset at the strike price, they can exercise the option. Exercising options is not mandatory and traders can exit at any time before expiration by selling the option.

In the case of American-style options, traders can exercise the option before the expiration date, while European-style options can only be exercised on the expiration date. If exercised early or in-the-money at expiration, the option holder will be in a short position in the underlying asset.

Put Options Strategy and Short Selling Stocks

For bearish investors, put options may be a more attractive strategy than shorting a stock. The theoretical risk of short selling a stock is unlimited because there is no upper limit on the stock price. At the same time, the profit potential of shorting a stock is limited because the stock cannot fall below $0 per share. Put options have similar profit potential as shorting a stock, as profits are similarly limited. The value of a put option will only increase if the underlying stock falls to zero. The advantage of a put option is that the risk is limited to the premium paid for the option.

The disadvantage of a put option is that the price of the underlying asset must fall before the option expiration date, otherwise the amount paid will be lost.

To profit from short selling a stock, a trader sells a stock at a certain price in the hope of buying it back at a lower price. Put options are similar; if the underlying stock declines, the put option increases in value and can be sold at a profit. If the option is exercised, it would place the trader in a short position on the underlying stock, and the trader would then need to purchase the underlying stock to realize a profit on the trade.

Hedging using put options

Put options can also be used to hedge a long stock position against unexpected changes. This hedging strategy is called a protective put or married put.

For example, assume an investor is long 100 shares of Bank of America Corporation (BAC) at a price of $25 per share. While investors are bullish on the stock over the long term, they are concerned that the stock could fall over the next month. Therefore, an investor pays$0.10 (multiplied by 100 shares since each put represents 100 shares) to purchase a put option with a strike price of $20 that will expire in one month.

The investor's hedge limits losses to $500, or 100 shares × ($25 - $20), less the premium paid for the put option ($10 total). In other words, even if Bank of America falls to $0 next month, this trader would lose at most$510 because all stock losses below $20 are covered by puts.

Example using put options

Assuming Apple Inc. (AAPL) trades at $170 a share, you think the price could drop about 10$155, paying $0.45. Your total put cost is$450 plus fees and commissions (1,000 shares × $0.45 =$450).

If Apple stock falls to $154 before expiration, your put option has a present value of$1.00 because you can exercise the option to short 1,000 shares at $155 and then immediately buy them back at$154 to hedge.

Your total put option value is currently $1,000 (minus any fees and commissions), which is (1,000 shares ×$1.00 = $1,000). Your profit on this position is 122$1,000 - $450)/$450. By buying the put option, you realized gains well above the 9.4% decline in the underlying stock price.

Conversely, if Apple shares rise to $200, those 10 option contracts will expire, costing you the$450 you originally invested.

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