If current implied int rate volatility will exceed future realized int rate volatility then hedge volatility risk dynamically. --OK -Lenghthen duration by purchasing futures after Interest went down -Shorten duration by selling futures after Interest have risen I don’t understand the logic of buying/selling futures. Please somebody explain

can´t do it without a graphic… if you draw the curve with negative convexity, you will see that, compared to the slope (duration), when you go to the left it doesn´t go up that much, and when you go to the right it goes down much more you offset this with the futures: if rates go down, you want more slope = more duration = buy futures. if rates go up, you want less slope = less duration = sell futures

refer to the graph in the CFA book. it is well explained