Last Thursday, I sold Feb 52 puts on GDX for 1.50. Even though GDX is now lower, the puts have lost value and are now only worth 1.13. I'm in the money on this trade because time decay works in the favor of options sellers.

This morning, I bought GDX - so I'm under water on this one. In both cases I was early (a nice way to say wrong). It's a real good example of why I prefer to sell puts, rather than buy the ETF outright (I bought it today because I wanted to use my registered account and they don't let me sell naked puts).