  We discuss the properties of the gas of primordial `stringy' black holes
possibly formed in the high-curvature phase preceding the bouncing transition
to the phase of standard cosmological evolution. We show that the regime
dominated by such a string-hole gas can be consistently described by explicit
solutions of the string effective action including first-order $\alpha'$
corrections. We present a phase space analysis of the stability of such
solutions comparing the results obtained from different actions and including
the possibility of $O(d,d)$-symmetric configurations.
