Quote from jwcapital:
And many will wait until the underlying hits their price target and then buy the put (at least 90 days our from expiration) at the strike nearest the price target. Heck, you can use options to get into a stock you like at the price you like as well. Suppose XYZ is trading at 50, but I like it at 45. So, I can sell the front-month 45 put. If it expires worthless, I can repeat the procedure and continue to pocket premiums. If it expires ITM, I still keep the premiums and I get the stock at the price I want. This requires patience. Then, once the stock hits my initial price target, I can buy a put at the strike closest to the price target. If this put expires ITM (assuming you allow it to), you lock in your stock profits minus the cost fo the put. If the stock keeps going up, you can always sell the protective put and buy another one as the stock reaches your next price target. Sure beats trailing stops---one dip and the trailing stop is hit, while the put doesn't do anything until expiration.