The Reserve Bank today said it is closely monitoring global developments like the credit downgrade of US and would continuously assess the impact on the Indian economy and financial markets. Noting that India was not insulated from these developments, the RBI said it will respond quickly and appropriately to the evolving situation.A sharp fall in US equity markets on Thursday was followed by a downgrade in the long-term US sovereign rating by rating agency Standard & Poor's from triple 'A” to double A plus. The RBI said, the US downgrading has raised concerns of continuing turmoil in global financial markets, as investors re-allocate portfolios in response to heightened risk perceptions stemming from both developments.