Hyperloop is an emerging transportation system that minimises the air resistance by having the vehicle travel inside a de-pressurised tube and eliminates the wheel-rail contact friction by using an electro-magnetic suspension system. Due to the very large target velocities, one of its challenges will be ensuring the system stability. This study aims to determine the velocity regimes in which the system is unstable and, more specifically, is focusing on the interplay between two fundamentally different instability sources, namely (i) the electro-magnetic suspension and (ii) wave-induced instability. To this end, unlike previous studies, the frequency and velocity dependent reaction force provided by the infinite guideway is properly accounted for. Results show that the interplay between the two instability mechanisms does not lead to significant qualitative changes compared to considering each one separately. This study can help Hyperloop engineers avoid excessive vibrations that can cause fatigue problems and, in extreme cases, derailment.@en