convexity is a good thing to have all else equal, the fixed income security with more convexity will loose less value when rate go up. S2K wisely pointed out that it has to be considered in the context of the other attributes of the security if there is a question on it
If effective convexity (Ceff) is positive, the price effect is positive, no matter what the price effect of duration is
If effective convexity (Ceff) is negative, the price effect is negative, no matter what the price effect of duration is
If effective duration (Deff) is positive, the price effect is negative when Δ_y_ is positive and positive when Δ_y_ is negative, no matter what the price effect of convexity is
If effective duration (Deff) is negative, the price effect is positive when Δ_y_ is positive and negative when Δ_y_ is negative, no matter what the price effect of convexity is