Nature Reviews Physics, Published online: 22 June 2026; doi:10.1038/s42254-026-00950-9 Radioactive molecules containing octupole-deformed nuclei offer a promising platform for measuring fundamental symmetry violations and searching for new physics. This Perspective discusses how advances in their production, trapping and molecular quantum control are enabling precision tests of fundamental physics at energy scales complementary to those probed by high-energy colliders.