  We show that several features of the Jackiw-Teitelboim model are in fact
universal properties of two-dimensional Maxwell-dilaton gravity theories with a
broad class of asymptotics. These theories satisfy a flow equation with the
structure of a dimensionally reduced TTbar deformation, and exhibit chaotic
behavior signaled by a maximal Lyapunov exponent. One consequence of our
results is a no-go theorem for smooth flows from an asymptotically AdS2 region
to a de Sitter fixed point.
