Banks are often called as a proxy for the economy. What happens when banks grow too big in size? They become even more critical for the overall stability of the system. Their failure can upset the whole financial markets, eroding the trust of investors. In other words, these banks then become ‘to-big-to-fail' banks. Hence, in 2015, the Reserve Bank of India (RBI) decide to tag big banks as Domestic Systemically Important Banks (D-SIBs) and asked them to beef up capital strength to guard against shocks. RBI's caution is understandable as banks are the first to take a hit during an economic crisis. Right now, there are three D-SIBs in India—SBI, HDFC Bank and ICICI Bank.