Including works by the most well-known names, from Monet and Matisse to Renoir and Rothko, there are 300 Picassos in their collection that are worth some $900 million. The Nahmad siblings generally buy and sell their works at auction. Ezra Nahmad is ranked as the 2nd richest person in Monaco, thanks to the joint art inventory worth some $3 billion, split 50/50.