The Standard Model cannot explain the dominance of matter over anti-matter in our universe, which indicates the existence of undiscovered time-reversal (T) symmetry violation. Proposed particle physics theories predict new particles that violate T-symmetry, which generically induce an electric dipole moment in the electron (eEDM). I will present the most precise measurement of the eEDM to date using electrons confined inside molecular ions, subject to a huge intra-molecular electric field, and evolving coherently for up to three seconds. Our result is consistent with zero and improves on the previous upper bound of the eEDM by a factor of ∼ 2.4. Our sensitivity to 10^−19 eV shifts in molecular ions provides constraints on broad classes of new physics at energies an order of magnitude beyond the direct reach of the Large Hadron Collider.