See how a bond's price responds to a yield shock Δy, and how accurately duration (the tangent) and convexity (the curvature) predict that change.
Duration and convexity approximate how a bond's price reacts to yield changes. This tool compares the exact price–yield curve with the first-order duration line and the second-order duration-plus-convexity parabola, so you can see how large a yield shock each approximation can handle.
For small yield moves. As the move grows, the curvature of the price–yield relationship makes the straight duration line underestimate the price, and the convexity term becomes significant.
With positive convexity the price rises more when yields fall than it drops when yields rise by the same amount, so for equal duration the more convex bond performs better under large rate moves.