The Castor Moving Group, or Castor stream, is a moving group of stars sharing similar velocities and directions. The stars that have been identified as part of the group include Castor, Fomalhaut, Vega, α Cephei and α Librae. While the reported group members are young (typically with ages of hundreds of millions of years), recent results suggest that the velocity differences amongst the moving group stars are too large for them to have possibly shared a common origin.