Hi MOB
There is the theory of "max pain". That is the tendency for the stock price to "pin" at the strike where the maximum number of options expire worthless. The theory is, that it occurs as option market makers try to get themselves flat by buying and selling stock, forcing the price towards the strike price.
It is not a conpiricy or a plot to rip off retail traders, just market forces at the big end of town... supply and demand under special circumstances
Like all market maxims, it is absolutly true, and can be traded....sometimes.
Other times, other market forces may completely overide this phenominum.
It is one to watch if you have the time. I don't really bother too much myself.
cheers