As every year, the Group Leaders League (publisher of the magazine makers) publishes a new edition of its ranking on best investment banks specializing in complex operations and stock exchange battle. Working tool for companies, this classification of investment banks is performed after an investigation of several months. To this end, investigators League Leaders group had contact with legal professionals of the most reputable business (investment banks, financial advice, entrepreneurs, investment funds ...). Questionnaires were sent by the hundreds. Our rankings are based on several criteria. Among them retain the reputation of the firm, the expertise of partners and their ability to impose on reference board records. The departments of revenue and studied the growth and dynamism of the teams are also criteria that may impact on the place of the teams in the standings. Other industry professionals (lawyers, bankers, advice, investors, investment funds, LBO actors) are also asked to comment on the position of commercial banks in our rankings.