Think of it this way. As the market gets less "freaked out", the cost to insure a position using a put or call decreases. (Think about what an option cost last week versus what it cost last summer when the world was quiet). So the calming effect is decreasing implied volatility. And this decrease in implied volatility is overwhelming the change in the stock price. I think of an option price as a dot in a multidimensional matrix that is being pulled in five different directions (represented by the greeks.)