It's hard to think about the stock market of 2015 right now. It's overshadowed by a grim start for 2016 with the S&P down 2.5 percent on the first trading day of the year.

But, looking back at the year that was, the market was flat in 2015. It ended right about where it started, actually down a half of a percentage point on the S&P.

Within that market were the best and worst performing stocks. The best stock gained 139.2 percent.

The stock you wish you would of had is Netflix (NFLX). The video-streaming stock was bolstered by original programming, cheaper pricing than traditional cable networks and the "cord-cutting" trend in which cable subscribers are trimming or eliminating their service completely in favor of digital upstarts like Netflix.

Coming in number two was Amazon (AMZN) at a gain of 122 percent. And the third best performing stock was Activision Blizzard (ATVI). The pure-play online gaming stock was up 95.7 percent.

Now for the worst performing stock in 2015. Chesapeake Energy (CHK), the oil and gas producer, was down 77.5 percent decimated by the horrific bear market in oil. The stock is having its worst year since 1998, according to Bloomberg.