  We argue that "stringy" effects in a putative gravity-dual picture for
SYK-like models are related to the branching time, a kinetic coefficient
defined in terms of the retarded kernel. A bound on the branching time is
established assuming that the leading diagrams are ladders with thin rungs.
Thus, such models are unlikely candidates for sub-AdS holography. In the weak
coupling limit, we derive a relation between the branching time, the Lyapunov
exponent, and the quasiparticle lifetime using two different approximations.
