A systematic investment plan, or SIP, is a way of investing a fixed amount in a mutual fund at a fixed interval, usually every month. The money buys more units when prices are low and fewer when prices are high, which averages out the cost. Indians put a record Rs 32,297 crore into SIPs in August 2026, through more than 10 crore active SIP accounts. A SIP of Rs 10,000 a month at 12% a year grows to about Rs 23 lakh in ten years on Rs 12 lakh invested.
A SIP is not a product. It is a method. The investor picks a mutual fund, an amount and a date, and the fund house debits the bank account and allots units on that date every month. The method solves two problems at once. It removes the need to time the market, and it turns saving into a habit that runs without decisions. Both matter more than fund selection for most people.
How a SIP works
Suppose Rs 10,000 goes into an equity fund on the 5th of every month. If the fund's unit price is Rs 100, the investor gets 100 units. If the market falls and the price drops to Rs 80 the next month, the same Rs 10,000 buys 125 units. If it rises to Rs 125, it buys 80. Over time the average cost per unit ends up lower than the average price, because more units were bought when it was cheap. This is called rupee cost averaging. It does not guarantee a profit. It does mean a market fall early in a SIP helps rather than hurts.
What the numbers look like
Rs 10,000 a month for ten years is Rs 12 lakh invested. At a 12% annual return, which is roughly what Indian equity has delivered over long periods, it grows to about Rs 23.2 lakh. At 15 years the same SIP reaches about Rs 50 lakh on Rs 18 lakh invested. The gap widens with time because the early instalments compound longest. A step-up SIP, where the amount rises by 10% every year with salary, roughly doubles the final corpus over 15 years. The maths is worked through in the step-up SIP calculator.
SIPs in India today
SIPs have become the main way Indian households own equity. Monthly SIP inflows reached a record Rs 32,297 crore in August 2026, up 14% on a year earlier, and the number of SIP accounts that actually paid in that month crossed 10 crore for the first time. SIP money now makes up more than a fifth of the mutual fund industry's assets. This steady inflow is one reason Indian markets have held up through foreign selling in recent years. Domestic investors keep buying on the 5th and the 10th whatever the headlines say.
Should a SIP be stopped in a falling market?
This is the question every new SIP investor asks in their first bear market. The arithmetic says no. The instalments made at low prices are the ones that do the most work later. Stopping in a fall and restarting after a recovery is the single most common way SIP investors underperform their own funds. The case is laid out in should you stop your SIP when the market falls. The exceptions are a real cash emergency or a fund that has changed its mandate.
Choosing a fund and a date
For most investors a low-cost index fund or a large-cap fund is the sensible core, with the fund's category chosen from the types of mutual funds SEBI defines. The date does not matter. Studies of Indian data find no meaningful difference between SIPs on the 1st, 10th or 25th. What matters is that the debit lands a day or two after salary, so the money is invested before it is spent. SIPs can be started with as little as Rs 100 a month at some fund houses, paused for a few months, or topped up at any time. The basics, including how to set one up, are in what is a SIP.
FAQs
Is a SIP the same as a mutual fund?
No. The mutual fund is the product. The SIP is the way of paying into it in instalments instead of a lump sum.
Can a SIP be done in stocks?
Some brokers offer a stock SIP that buys a fixed rupee amount of a share every month. It works the same way but without the diversification a fund gives.
How are SIP gains taxed?
Each instalment is treated as a separate purchase. Units held over a year in an equity fund are taxed at 12.5% above Rs 1.25 lakh of gains. Units held under a year are taxed at 20%.
What is the best SIP amount?
Whatever can be sustained for years without stopping. A Rs 5,000 SIP that runs for 15 years beats a Rs 20,000 SIP that stops after two.