The U.S. Securities and Exchange Commission (SEC) has closed its investigation into Gotham City Research, the firm that accused Spanish pharmaceutical company Grifols of deceptive accounting practices earlier this year. Despite the closure of the U.S. investigation, Spain's market regulator, the CNMV, has identified signs of market manipulation in the dispute between Gotham City Research and Grifols. The CNMV has decided to refer the case to the Spanish Prosecutor's Office for further scrutiny.