Recent estimates of the economy of the Mumbai Metropolitan Region is estimated to be $400 billion (PPP metro GDP) ranking it either the most or second-most productive metro area of India.[7][8] Many of India's numerous conglomerates (including Larsen & Toubro, State Bank of India (SBI), Life Insurance Corporation of India (LIC), Tata Group, Godrej and Reliance),[3] and five of the Fortune Global 500 companies are based in Mumbai.[9] This is facilitated by the presence of the Reserve Bank of India (RBI), the Bombay Stock Exchange (BSE), the National Stock Exchange of India (NSE), and financial sector regulators such as the Securities and Exchange Board of India (SEBI).[5]