In December 2014, investors who had purchased American Depository Shares (ADSs) of Petrobras on the New York Stock Exchange filed a securities class action in the Southern District of New York, alleging violations of the Securities Act of 1933, the Securities Exchange Act of 1934 , and (in an amended complaint) Brazilian securities laws.
What is the relationship between 'Petrobras' and 'New York Stock Exchange' in the context of the input sentence.
Options: industry, currency, developer, stock exchange