Experimental results show that the peak velocity, peak electric field, and saturated velocity of the velocity–electric‐field curve forn‐GaAs all increase substantially with increasing hydrostatic pressure up to about 10 kbar; the peak velocity and field then begin decreasing with further increase in pressure. The extraction of the data from the current‐voltage characteristics is based on an exploitation of the influence of the boundary conditions on the manifestation of transferred‐electron‐induced (Gunn) current instabilities.