Till now, there were five passively managed funds in Mint50, with a mix of index funds and exchange traded funds (ETFs). Typically, we prefer ETFs because of their superior structure, low tracking error and therefore lower costs compared to index funds at large. But ETFs also have disadvantages, one of which is lack of liquidity. On many days, not enough ETF units are available for sale, and not always at the price you may want them for. Also, their price rises as the amount bought goes up.
