Abstract We use an event study approach to estimate the burden of the financial regulations associated with Systemically Important Financial Institution (SIFI) designation. On March 30, 2016, the US District Court determined that MetLife’s SIFI designation was arbitrary and capricious because the Financial Stability Oversight Council (FSOC) failed to weigh the economic cost of the financial regulation on MetLife against the benefits of increased financial stability. We find significant positive abnormal returns for MetLife and AIG on the date of the ruling. We estimate that the lifting of the SIFI designation created $1.4 billion in corporate wealth for MetLife, suggesting that MetLife would be 3.4% more profitable as a non-SIFI. These gains fall short of the $8 billion stipulated by MetLife in its complaint. We also find significant abnormal returns to SIFI institutions on the day following the US Presidential election.