Marcin Mazurek shares interesting financial insights on the major bank challengers in Europe. A review of operations of major bank challengers after a year of significant challenges offers some interesting insights.   Slower customer growth The group of major* players representing top bank challengers in Europe (Revolut, N26, Monzo, Monese, Starling, TransferWise, Curve, and Tandem) served nearly 39 million customers as of Q4 2020 as compared to nearly 27 million as of Q4 2019. What is striking here is…