Recent advances in electroweak baryogenesis opened up a significant part of the parameter space where strong transitions lead to hypersonic bubble wall velocities. I will discuss the interplay of baryon yield and gravitational waves produced by the underlying phase transition. Specifically I will focus on the assumption of the development of a steady state for the bubble-fluid system and show it is not always true. This problem puts into question the calculations for relatively strong transitions and tends to increase the mismatch between scenarios predicting a significant baryon yield and observable gravitational wave signals.