What is a SIP?
A plain-language explainer of systematic investment plans: how they work, why cost averaging and compounding help, and how they compare to lump sums.
The basics
A systematic investment plan, or SIP, is a way to invest a fixed amount at regular intervals, usually monthly, into a mutual fund. Instead of trying to time a single large purchase, you automate a steady stream of small ones. That turns investing into a habit rather than a decision you have to make and re-make, which is one reason SIPs are popular with people building wealth gradually from a salary.
Rupee or dollar cost averaging
Because you commit the same amount each period, the number of fund units you buy changes with the price. When the market dips your fixed sum buys more units, and when it rises it buys fewer. Over many months this averages out your purchase price and takes the pressure off predicting the perfect entry point. It does not guarantee a profit, but it smooths the emotional swings that lead investors to buy high and sell low.
The power of compounding
The returns your investment earns start earning returns of their own, and over long horizons that snowball dominates the outcome. In the calculator you can see this in the widening gap between the amount invested and the projected value. Early contributions matter most because they have the longest time to compound, which is why starting sooner, even with a smaller amount, often beats starting later with more.
SIP versus a lump sum
A lump sum invests everything at once, so if markets rise steadily it can outperform a SIP because the full amount is exposed from day one. A SIP spreads entry over time, which reduces the risk of buying right before a fall and suits people who earn and invest month to month. Neither is universally better; the right choice depends on whether you have a large sum available now and how comfortable you are with short-term volatility.