I have a very important question.

Is “Positive butterfly” the same thing with “positive butterfly spread”?

My understanding is that “Positive butterfly” means “negative butterfly spread” since according to the formula, positive butterfly will result in a negative number(so that I call it “negative butterfly spread”???). Can someone tells me if “positive butterfly spread” actually means “positive butterfly”???

No.

The former describes a * change* in the shape if the yield curve (medium-term yields decreasing relative to short-term and long-term yields), while the latter is a

*of the shape of (specifically, the amount of curvature in) the yield curve.*

**measure**The term negative and positive butterfly spread shouldn’t be used then no? It should be a positive butterfly leads to a decrease in butterfly spread then.

Or can we say a positive butterfly equates to a negative butterfly spread?