To trade options, you also need to make sure you know whether the trade is an American option or a European option. The buyer of the American option can change the exercise price to the underlying asset at any time prior to expiration. Conversely, buyers of European options can only exercise their rights on the expiration date. Despite this, in fact many of the option positions are flattened before the due date and never exercised. This is also what we need to know when learning foreign exchange knowledge. Another factor to consider is "time loss”. This means that as the expiration date of the option approaches, the value of the option will fall at a faster rate, and the potential for fluctuations before it expires becomes smaller and smaller. Time loss is not good for the option buyer, but in turn favors the option seller. For example, if you have already bought a call option, you may be able to make a profit if the price of the underlying price rises adequately, and your downside risk (here, downside risk refers to the worst possible scenario when investing, or maybe The losses that need to be incurred. The upside risks are the opposite.) Only the premiums you pay. At any time before the expiration, the price may rise sufficiently to generate greater profits. However, as the expiration date approaches, this possibility is diminished and the final value of the option becomes the difference between the strike price and the underlying asset price minus the paid premium. That is to say, as an option buyer, your downside risk begins to appear, but it is still limited to the premium paid, and the theoretical upside risk is still unlimited. Time loss is used to try to achieve this unlimited upside potential. For option sellers, the potential profit is certain. It is impossible for the seller to obtain a gain over the premium. However, the downside risks are limitless. If you sell or say short call options, and the price goes up strongly, you will lose money. Similarly, if you sell or say short put options, and the price falls, you may lose money. Time loss is to try to achieve this unlimited downside risk. Every day, the likelihood of a worst-case situation will drop. The Greek letter in the stock option is also a point we need to understand. For those who are serious about trading options, it is worthwhile to further study the Greek letters in the options. These letters are indicative of things such as implied volatility, which is the rate at which the value of the premium follows the price of the underlying instrument. These are all reflected in Greek letters. 1.Delta: measures the impact of changes in the price of the underlying instrument on the price of the option. 2. Gamma: The effect of changes in the price of the underlying instrument on the delta is measured. 3. Lambda: indicates the percentage change of the option price corresponding to the percentage change of the target instrument price. 4.Theta: It measures the impact on the option price as the expiration approaches —— measures the time loss. 5. Rho: Represents the effect of interest rate changes on option prices. 6.Vega: Measure the change in the price of the option when the volatility changes.