We have studied the high electric field conductivity of n-type InAs at pressures up to 29 kbar. Carrier multiplication due to impact ionization of valence band electrons is the predominant phenomenon at lower pressures, while the Gunn effect is observed at higher pressures. Above about 25 kbar no carrier multiplication is observed below the threshold electric field for Gunn effect. The bulk negative differential conductivity underlying the Gunn effect is presumed to be due to the transferred carrier mechanism. From the change in character of the high-field transport near 25 kbar, and from some recently published studies on the In1-xAlxAs alloy system, we eliminate the subsidiary minima involved in the carrier transfer to lie about 1.2±0.05 eV above the top of the valence band at atmospheric pressure, and to have L1 symmetry. The results are compared with an earlier report of Gunn effect in InAs under uniaxial stress. © 1971 The American Institute of Physics.