SIP or lump sum?
How a monthly SIP and a one-time lump sum differ, what rupee-cost averaging really does, and how to decide.
A SIP (systematic investment plan) puts a fixed amount into a fund every month. A lump sum puts it all in at once. Neither is always better. They solve different problems.
What a SIP does well
- It matches how most people earn. Money comes in monthly, so investing monthly is natural.
- It buys more units when prices are low. A fixed ₹5,000 buys more units after a fall and fewer after a rally. This is “rupee-cost averaging”. It doesn’t guarantee a profit, but it softens the effect of bad timing.
- It builds a habit. The biggest risk for most investors isn’t the market, it’s stopping. An automatic SIP keeps going through scary headlines.
When a lump sum does better
If you already have a large amount (a bonus, a matured deposit), markets have historically risen more often than they’ve fallen, so investing it all at once has more often ended ahead of spreading it out. But “more often” isn’t “always”. If a big fall comes right after you invest, a lump sum hurts, emotionally as well as financially.
A practical middle path
- Monthly income: run a SIP.
- A large amount and you’re nervous: park it in a liquid fund and move it into equity in equal parts over 6–12 months (a systematic transfer plan, or STP).
- A large amount and a long horizon, and you can stay calm through a fall: a lump sum is reasonable.
See it with real numbers
The fund explorer has a SIP check. Pick a fund, a monthly amount and a start month, and it shows what the SIP would be worth today at the fund’s real past NAVs, with the annual return (XIRR) that accounts for when each instalment went in.
Educational only, not advice for your situation.