 Scaling invariance of SLE

For every $a>0$, if $(K_t)$ is ${\mathrm{SLE}}_{\kappa }$, then $(a^{-1}{K}_{a^{2}t})$ has the same law. Its driving function is $a^{-1}{U}_{a^{2}t}$, which has the same law as $U_t$ by Brownian scaling.