SIP refers to periodic investment in an MF. In this option, you commit to invest a pre-decided amount, at regular intervals, and you get allotted Units based on an MF’s NAV. E.g. Suppose you do an SIP of Rs. 1,000. If, for the 1st month its NAV is Rs. 15, you get 66.67 units. For the 2nd, the NAV is Rs. 25, so you get 40 units. For the 3rd, the NAV is Rs. 20, you get 50 units. At the end of 3 months, you have invested Rs. 3,000 and received 156.67 units at an average NAV of Rs. 19.2.