Mutual funds are still not the mainstay of investment, though have a high rate of adoption due to SIPs. Stock Market Despite strong SIP inflows and the growing reach of mutual funds in smaller cities, India remains one of the least-penetrated large economies in terms of mutual funds, as the chart above shows.The US leads the comparison, with mutual fund assets under management (AUM) equal to 124% of its GDP. This is the result of decades of retirement savings through institutions such as 401(k) plans, along with a strong culture of investing in stocks and mutual funds.India, at 19.9 percent,…