When a normally publicity-shy company comes out of the shadows, observers are right to be a little wary. Particularly if that firm has a murky past and is the leading player in markets that have recently enjoyed a spectacular bull run.
Last week, Glencore announced plans to raise $12 billion in a global initial public offering. With a 20% stake on sale, the deal would value the Zug-based commodities trader at around $60 billion. The company has grown rapidly since management bought out controversial former tax-fugitive Marc Rich for $600 million in 1994. It now dominates trading in base metals, is prominent in soft commodities such as wheat, and...