The 7-5-3-1 rule of SIP is a simplified investment strategy. In it, '7' means investing in equity funds for minimum of 7 years and '5' signifies having 5 different types of equity funds in portfolio. Meanwhile, '3' represents the three challenging phases of SIP (disappointment- 7-10% returns, irritation- 0-7% returns, panic- negative returns), and '1' means increasing investment every year.