Do you think aerodynamic socks are only good for looking like a pro? So think again; they help you to be faster!
During riding, the wind blows on our legs. It cuts in the front and then swirls in the back of the leg, increasing friction and decreasing our speed. Aerodynamic socks are made of a unique fabric that "straightens out" the wind flow, prevents turbulence, and increases the efficiency of your paddling.
Now you understand why the UCI regulates sock length.