In the video below, Motley Fool financial analyst David Hanson takes a look at an interesting bet that Goldman Sachs (GS -0.20%) is making in Europe. The company is building a new office building in London that may become its European headquarters, at a time when several other prominent European banks are scaling back their investment banking businesses. David tells investors why this move may be indicative of an opportunity for American investment banks to step in and grab European market share.