Option Series

See: Option Class.

An option series separates calls and puts. We know, not very enlightened. Maybe, one day, puts and calls can choose their own series. But we haven't reached that point yet.

For now, a particular series includes either all the calls or all the puts for a single underlying asset, with the same strike price and the same expiration. So calls for NFLX with a strike price at $360 and a July expiration would count as one series; meanwhile, puts for NFLX with a strike price at $360 and a July expiration would represent another series.