云上日照

卖出看跌期权（Short Put）的损益平衡点计算公式与理解：

损益平衡点 = 行权价 - 权利金（期权费）

详细解析：

1. 定义：

• 行权价 (Strike Price)：期权合约中约定的买入价格。

• 权利金 (Premium)：你作为卖方，在卖出期权时立即收到的收入。

2. 逻辑推导：

• 当你卖出看跌期权时，你最大的收益是收到的权利金。你的义务是：如果股价跌破行权价，你必须按行权价买入股票。

• 如果标的资产价格下跌低于行权价，买方会行权，迫使你以高于市场的价格买入股票，从而产生亏损。

• 当标的资产价格下跌的幅度（即：行权价 - 当前股价）正好等于你收到的权利金时，你的亏损抵消了之前的收入，此时总盈亏为0。

• 因此，平衡点就是 行权价 - 权利金。

3. 举例说明：

• 若到期股价 > $100：期权作废，你赚取全部 $4 权利金（盈利）。

• 若到期股价 = $96：买方行权，你被迫以$100买入市价为$96的股票，每股亏损$4，但这正好被收到的$4权利金抵消，你不赚不赔（平衡）。

• 若到期股价 < $96：例如股价跌至$90，你被迫以$100买入，每股亏损$10，扣除$4权利金后，净亏损$6（亏损）。

• 行权价：$100

• 收到权利金：$4

• 假设你卖出一张股票看跌期权：

• 损益平衡点 = $100 - $4 = $96

• 结果分析：

4. 风险提示：

• 卖出看跌期权的最大风险发生在标的资产价格归零时。

• 最大亏损 = (行权价 - 权利金) × 合约单位。虽然风险很大，但它是有限的（因为股价最低只能跌到0），这与卖出看涨期权的无限风险不同。

The formula for calculating the break-even point of a short put option is also very straightforward:
Break-even point = Strike price - Premium (Option premium)
Detailed analysis:
Definition:
Strike price: The agreed-upon purchase price in the option contract.
Premium: The income you receive immediately as the seller when selling the option.
Logical deduction:
When you sell a put option, your maximum gain is the premium you receive. Your obligation is that if the stock price falls below the strike price, you must buy the stock at the strike price.
If the price of the underlying asset drops below the strike price, the buyer will exercise the option, forcing you to buy the stock at a price higher than the market price, resulting in a loss.
When the decline in the price of the underlying asset (i.e., strike price - current stock price) is exactly equal to the premium you received, your loss offsets your previous income, and the total profit and loss is zero.
Therefore, the break-even point is the strike price minus the premium.
Example:
Suppose you sell a put option on a stock:
Strike price: $100
Premium received: $4
Break-even point = $100 - $4 = $96
Result analysis:
If the stock price at expiration > $100: The option expires worthless, and you earn the full $4 premium (profit).
If the stock price at expiration = $96: The buyer exercises the option, forcing you to buy the stock at $100 when the market price is $96, resulting in a loss of $4 per share. However, this is exactly offset by the $4 premium you received, and you neither gain nor lose (break-even).
If the stock price at expiration < $96: For example, if the stock price drops to $90, you are forced to buy at $100, resulting in a loss of $10 per share. After deducting the $4 premium, your net loss is $6 (loss).
Risk warning:
The maximum risk of selling a put option occurs when the price of the underlying asset drops to zero.
Maximum loss = (Strike price - Premium) × Contract unit. Although the risk is significant, it is limited (because the stock price can only fall to zero at most), which is different from the unlimited risk of selling a call option.