how can a stock go down anthe put option go down the same day?

TeachMeMore answered one year ago …

It could be for a number of reasons:

1. Did IBM pay some kind of special dividend? That happened when MSFT announced that onetime special dividend. The options dropped.

2. Implied Volatility went down, thus causing the price of the option to decrease. Check out the definition here:

"A theoretical value designed to represent the volatility of the security underlying an option as determined by the price of the option. The factors that affect implied volatility are the exercise price, the riskless rate of return, maturity date and the price of the option. Implied volatility appears in several option pricing models, including the Black-Scholes Option Pricing Model."

http://www.tickerhound.com/dictionary/word/5611/implied-volatility