According to the Tax Justice Network latest Financial Secrecy index Switzerland is the largest tax haven followed by the US. Third on the list is the Cayman Islands. The US move to second largest tax haven is due to the refusal of the American government to sign the OECD’s Common Reporting Standard.
Read more here: //www.internationalinvestment.net/products/tax/us-now-worlds-second-largest-tax-haven-switzerland-report/