SIPSIP
Investing a fixed sum every month — the habit, not a product, that built India's mutual fund industry.
Why you care
A SIP is not a product you buy — it's an instruction: invest a fixed sum, on a fixed date, every month, automatically. That's the whole trick. It removes the two things that wreck investors, timing the market and forgetting to invest, and replaces them with a standing instruction. You can run a SIP into almost any fund.
Run the numbers
₹10,000 a month for 20 years is ₹24 lakh invested. At a 12% return it grows to roughly ₹99 lakh (illustrative). Most of that ₹99 lakh is growth on money you put in years ago — the corpus is built by time and consistency, not by any clever market call.
Where this goes
Why you care
A SIP (Systematic Investment Plan) is a standing instruction to invest a fixed amount in a chosen fund at a fixed interval, usually monthly, on autopilot. The single most important thing to understand about it is that it is a mechanism, not a product. There is no "SIP fund." You run a SIP into an equity fund, an index fund, a hybrid — the SIP is just the way the money goes in. Confusing the habit with the product is the most common beginner error.
Its power is behavioural before it's mathematical. Two things destroy retail investors: trying to time the market (buying after it's risen, selling after it's fallen), and simply never getting around to investing. A SIP kills both. It invests on a schedule regardless of how the market feels, so you can't chicken out at the bottom or pile in at the top. And it happens automatically, so discipline doesn't depend on willpower each month. On top of that it delivers rupee-cost averaging as a free side effect. This combination is why India's fund industry was effectively built on the SIP, and why monthly SIP inflows have become the steady, sticky base under the whole business.
Run the numbers
₹10,000 a month into an equity fund, for 20 years, at a 12% assumed return (illustrative):
| Value | |
|---|---|
| Total invested (₹10,000 × 240 months) | ₹24 lakh |
| Corpus after 20 years | ~₹99 lakh |
| Of which, your contributions | ₹24 lakh |
| Of which, growth | ~₹75 lakh |
Three-quarters of the final corpus is growth, not contribution, and it came from letting early instalments compound for close to two decades. Notice what you did not do to earn it: pick tops and bottoms, react to news, or add lump sums when things "looked cheap." You set an instruction and left it alone. The discipline is the strategy. This is also why stopping a SIP in a downturn is so costly, because those are exactly the low-priced months doing the most work.
Where this goes
The SIP's mechanism is rupee-cost averaging: a fixed rupee amount automatically buys more units when the NAV is low and fewer when it's high. Because the money goes in over time rather than at once, the honest measure of a SIP's return is its XIRR, not a simple CAGR. And zoomed out to the whole industry, millions of individual SIPs sum into the SIP book. It's the predictable monthly inflow that behaves, for a fund house, much like sticky CASA deposits do for a bank.
What causes what
After this
- SIP causesRupee-Cost AveragingBuying a fixed rupee amount every month is the mechanism that averages your cost per unit.
- SIP causesThe SIP BookEvery individual SIP adds to the industry's sticky monthly recurring inflow.
- SIP causesXIRRBecause a SIP invests in instalments, XIRR is the only honest way to measure its return.
- SIP causesFolio GrowthMost new folios are opened to start a SIP — the habit spreading is what widens the investor base.