In the art market, David Martinez is known as the buyer of a $140m Jackson Pollock and the controversial seller of a $31.4m Rothko he bought from Marguerite Hoffman. But little has been known about Martinez’s investing until now.

Bloomberg uses regulatory filings to sketch out the scope of his business:

He wrote in a 2013 Financial Times column that his firm participated in almost every sovereign debt restructuring of the past quarter century, from Latin America in the 80s to Greece four years ago.

Regulatory filings in Spain, Italy, Mexico, Argentina and the U.S. sketch a picture of activity across three continents. Fintech’s holdings include minority stakes in two of Europe’s oldest financial institutions, Spain’s Banco de Sabadell SA and Italy’s Monte dei Paschi di Siena SpA.

The bulk of his investments appear to be in Argentina. He bought sovereign debt there more than a decade ago and made millions repurchasing discounted bonds. Fintech in 2007 became a 40-percent owner of Cablevision SA, whose parent Grupo Clarin SA is the country’s most powerful media group.

Mysterious Bond-Market Billionaire Offers Rare Look at Finances  (Bloomberg)