What is a SIP and How Does It Work?
⏱ 2 min readA SIP — Systematic Investment Plan — is simply a standing instruction to invest a fixed amount into a mutual fund every month. It is not a product in itself, just a disciplined way of buying one. Here is how it works and why it became India's default way to invest.
SIP in one minute
On a date you choose, a fixed amount (often as little as ₹500) moves from your bank account into a mutual fund of your choice, buying units at that day's NAV. That's the whole mechanism — repeated monthly, for years.
The power is in what the repetition does: it removes the decision of when to invest, which is exactly the decision most investors get wrong.
Rupee cost averaging: buying more when it's cheap
Because the amount is fixed, your money automatically buys more units when prices fall and fewer when they rise:
- Month 1 — NAV ₹50: ₹5,000 buys 100 units
- Month 2 — NAV ₹40 (market dips): ₹5,000 buys 125 units
- Month 3 — NAV ₹55: ₹5,000 buys ~91 units
- Your average cost ends up below the average price — dips work for you instead of scaring you out.
Compounding needs time more than amount
A ₹10,000 monthly SIP at an assumed 12% annual return grows to roughly ₹1 crore in 20 years — of which only ₹24 lakh is money you put in; the rest is growth on growth. Halve the time and the corpus falls to about ₹23 lakh, not half. The years matter more than the monthly amount.
What a SIP does not do
A SIP does not guarantee returns, does not eliminate market risk, and does not magically beat lump-sum investing in every scenario — it smooths your entry price and automates discipline. The fund you choose still determines what you actually earn.
SIPs are also flexible: you can pause, stop, increase (step-up SIP) or redeem without penalty in most open-ended funds (tax and exit loads aside).
Frequently asked questions
What is the minimum SIP amount?
Many funds accept SIPs from ₹500 a month (some from ₹100). The right amount is whatever you can sustain for years without pausing.
Does the SIP date matter?
Studies of Indian market data show date-of-month effects are negligible over long periods. Pick a date just after your salary credit so the debit never fails.
Can I lose money in a SIP?
Yes, especially over short periods — SIPs invest in market-linked funds. Historically, longer holding periods have sharply reduced the odds of loss in diversified equity funds, but nothing is guaranteed.