There are many different option buying strategies that investors can use, and the best strategy for you will depend on your investment goals and risk tolerance. Some common option buying strategies include:

1. Long call: This strategy involves buying a call option, which gives the buyer the right (but not the obligation) to buy the underlying asset at a predetermined price (the strike price) on or before a certain date (the expiration date). This strategy is best used when the investor expects the price of the underlying asset to rise.

2. Long put: This strategy involves buying a put option, which gives the buyer the right (but not the obligation) to sell the underlying asset at a predetermined price on or before a certain date. This strategy is best used when the investor expects the price of the underlying asset to fall.

3. Bull call spread: This strategy involves buying a call option with a lower strike price and selling a call option with a higher strike price. This strategy is best used when the investor expects the price of the underlying asset to rise, but not too sharply.

4. Bear put spread: This strategy involves buying a put option with a higher strike price and selling a put option with a lower strike price. This strategy is best used when the investor expects the price of the underlying asset to fall, but not too sharply.

5. Covered call: This strategy involves buying the underlying asset and selling a call option on that same asset. This strategy is best used when the investor expects the price of the underlying asset to remain relatively stable or rise slightly.

It's important to note that option buying strategies involve a certain level of risk, and it's important to understand the potential risks and rewards before implementing any strategy.