  We introduce a stochastic heterogeneous interacting-agent model for the
short-time non-equilibrium evolution of excess demand and price in a stylized
asset market. We consider a combination of social interaction within peer
groups and individually heterogeneous fundamentalist trading decisions which
take into account the market price and the perceived fundamental value of the
asset. The resulting excess demand is coupled to the market price. Rigorous
analysis reveals that this feedback may lead to price oscillations, a single
bounce, or monotonic price behaviour. The model is a rare example of an
analytically tractable interacting-agent model which allows us to deduce in
detail the origin of these different collective patterns. For a natural choice
of initial distribution the results are independent of the graph structure that
models the peer network of agents whose decisions influence each other.
