First a short lesson on options. A very basic lesson in laymens terms.
Option prices consist of intrinsic value and time value. Forget about intrinsic value for now. The main point of this post concerns time value. When you buy and sell options you are buying and selling time. The time value of an option is always decaying and the decay picks up steam the closer the option gets to expiration.
Ex: If an option is priced at 4 and the stock is at 50.....a week later if the stock is still at 50, the option can fall to 3. The stock hasnt moved but the time value has decayed. This is why selling options is a much easier strategy to perfect than buying options.
Heres how it works in real life.
Today I sold some put options on the SP500 index. They expire on Friday.
The SP500 tracking stock was trading at 136.13 when I made this trade. I sold the Jun 136 puts for 1.6 (thats $160 each and the contracts are for 100 shares each).
If the stock closes on Fri above 136, the option expires worthless and what I sold for $160 is now worth nothing. Whoever bought it from me for $160 now has an option worth $0.
As you can see, the stock was already above the 136 price. So the stock can move nowhere or even drop a bit and I still make the $160 per contract. That is the time value that will decay away in one weeks time.
One of 3 things will happen this week.
1) SPY will go up and obv be above $136. I keep the $160 per contract
2) SPY will go nowhere...I keep the $160 per
3) SPY will go down. It can go down 1.6 plus the .13 its above 136 for a total of 1.73 and put me at break even. If it drops more than that I lose money.
Nobody knows where the stock will move in one week. Its equally likely to go up as go down in any one week. I have 1.25% downside protection before I lose money.
So if you figure its 50/50 to go up or down, you can say i have a 1.25% overlay.