  We propose a new mechanism where asymmetric dark matter (ADM) and the baryon
asymmetry are both generated in the same decay chain of a metastable weakly
interacting massive particle (WIMP) after its thermal freeze-out. Dark matter
and baryons are connected by a generalized baryon number that is conserved,
while the DM asymmetry and baryon asymmetry compensate each other. This unified
framework addresses the DM-baryon coincidence while inheriting the merit of the
conventional WIMP miracle in predicting relic abundances of matter. Examples of
renormalizable models realizing this scenario are presented. These models
generically predict ADM with sub-GeV to GeV-scale mass that interacts with
Standard Model quarks or leptons, thus rendering potential signatures at direct
detection experiments sensitive to low mass DM. Other interesting
phenomenological predictions are also discussed, including: LHC signatures of
new intermediate particles with color or electroweak charge and DM induced
nucleon decay; the long-lived WIMP may be within reach of future high energy
collider experiments.
