The electron's electric dipole moment (EDM) must be collinear with the direction of the electron's magnetic moment (spin). Within the Standard Model of elementary particle physics, such a dipole is predicted to be non-zero but very small, at most 10 e ⋅cm, where e stands for the elementary charge. The discovery of a substantially larger electron electric dipole moment would imply a violation of both parity invariance and time reversal invariance.