  The symmetric orbifold of $\mathbb{T}^4$ is the CFT dual of string theory on
AdS$_3\times {\rm S}^3 \times \mathbb{T}^4$ with minimal NS-NS flux. We study
its symmetry algebra and provide evidence that it does not have any deformation
parameter. This suggests that the symmetric orbifold is (at least locally) the
most symmetrical CFT in its moduli space.
