Asha Reddy (an illustrative profile) is 30, works in Hyderabad and can invest ₹10,000 a month from her salary. Her father, Ashok, has just retired at 60 with ₹40 lakh and wants a monthly income without touching his capital. Both have chosen suitable funds. Now they face a second, equally important question: how should money go in, and how should it come out?
Mutual funds offer four main routes: SIP, lump sum, STP and SWP. This chapter explains each with real numbers, so you can see what each one actually does and where its limits lie.
In this chapter
- How rupee cost averaging in a SIP works, with a six-month example
- Why a yearly step-up matters so much over long periods
- When a lump sum or an STP makes sense
- How to size a SWP so that it lasts, and what can go wrong
The SIP: investing a fixed amount on a fixed date
A Systematic Investment Plan (SIP) invests a fixed amount, usually monthly, on a chosen date, through an automatic bank mandate. Because the rupee amount is fixed, you buy more units when the NAV is low and fewer when it is high. This is called rupee cost averaging.
Worked example: rupee cost averaging over six months. Asha invests ₹5,000 a month. Assume the NAV moves as follows (illustrative): ₹50, ₹45, ₹40, ₹44, ₹48, ₹52.
- Units bought each month: 100.00, 111.11, 125.00, 113.64, 104.17 and 96.15.
- Total units = 650.07 for a total investment of ₹30,000.
- Average cost per unit = ₹30,000 ÷ 650.07 ≈ ₹46.15, lower than the simple average NAV of ₹46.50.
- At the final NAV of ₹52, her holding is worth 650.07 × ₹52 ≈ ₹33,804, a gain of about 12.7%, even though the NAV is only 4% above where she started.
The fall in months two and three helped her, because her fixed ₹5,000 bought extra units cheaply. But notice the limits: if the NAV had kept falling, her SIP would have shown a loss. A SIP spreads your entry over time; it does not guarantee profit or protect against a long decline.
The bigger benefit of a SIP is behavioural. It ties investing to your salary, removes the temptation to time the market, and keeps you buying during falls, which is exactly when most investors are tempted to stop.
The step-up: letting your SIP grow with your salary
A flat SIP that never rises becomes a smaller share of your income every year. A step-up SIP raises the instalment by a fixed percentage each year, often in line with increments.
Worked example: flat vs step-up SIP. Assumptions (illustrative): Asha starts at ₹10,000 a month, the fund earns 12% a year compounded monthly, and she invests for 20 years.
- Flat SIP: total invested ₹24 lakh; estimated value ≈ ₹92 lakh.
- Step-up of 10% a year: the monthly amount rises to about ₹61,000 by year 20; total invested ≈ ₹68.7 lakh; estimated value ≈ ₹1.86 crore.
- The step-up roughly doubles the final corpus, because the larger later contributions still have years to compound.
Returns in real life will vary year to year, and 12% is an assumption, not a promise. The lesson holds regardless: increasing contributions matters as much as choosing funds.
Lump sum and STP: investing money you already have
A lump sum invests a large amount at once, such as a bonus, an inheritance or maturity proceeds. Because markets have tended to rise over long periods, investing at once has often worked out well historically, but it exposes the full amount to any fall that happens soon after.
A Systematic Transfer Plan (STP) is the middle path. You place the lump sum in a liquid or short-term debt fund and transfer a fixed amount into an equity fund every week or month. Suppose Asha receives ₹12 lakh and sets up an STP of ₹1 lakh a month for 12 months. Her entry into equity is spread across a year, and the money waiting in the liquid fund keeps earning; at an assumed 6.5% a year, that comes to roughly ₹42,000 over the year, before tax.
Two cautions apply. Each transfer is a redemption from the debt fund, so tax applies to any gain on it. And an STP does not make equity suitable for a short-term goal; it only smooths the entry for money that is already meant to be in equity for the long term.
The SWP: turning a corpus into income
A Systematic Withdrawal Plan (SWP) redeems a fixed amount from a fund each month and credits it to your bank account. It is widely used to create retirement income or to pay for a goal in instalments, such as college fees. Only the gain portion of each withdrawal is taxable, which we cover in the next chapter.
The critical question is the size of the withdrawal relative to what the corpus earns.
Worked example: will Ashok's SWP last? Assumptions (illustrative): corpus ₹40 lakh in a suitable hybrid or debt-oriented fund, a steady 8% a year, no change in withdrawals.
- Monthly growth at 8% a year ≈ 0.643%, or about ₹25,700 on ₹40 lakh in the first month.
- SWP of ₹25,000 a month: withdrawals are slightly below growth, so the corpus is still about ₹41.3 lakh after 10 years.
- SWP of ₹35,000 a month: withdrawals exceed growth, so the corpus falls to about ₹23.3 lakh after 10 years and runs out in roughly 17 years.
| Monthly SWP from ₹40 lakh | Corpus after 10 years | How long it lasts |
|---|---|---|
| ₹25,000 | About ₹41.3 lakh | Indefinitely, at a steady 8% |
| ₹35,000 | About ₹23.3 lakh | About 17 years |
Real life is less tidy. Returns are uneven, and a market fall early in retirement, while withdrawals continue, does lasting damage; this is called sequence risk. Inflation also means ₹25,000 will buy less each year. Many retirees therefore keep two to three years of withdrawals in low-volatility funds and review the SWP amount every year. The Retirement Planning module covers this in depth.
Which route for which situation?
| Situation | Route commonly used | Watch out for |
|---|---|---|
| Investing from monthly salary for a long-term goal | SIP with a yearly step-up | Stopping the SIP during market falls |
| A large sum for a long-term goal | Lump sum, or STP over 6–12 months | Tax on each STP transfer |
| Regular income from an existing corpus | SWP from a suitable fund | Withdrawals larger than growth; sequence risk |
| Goal 1–3 years away | SIP or lump sum into debt or conservative funds | Using equity for short-term money |
Common mistakes to avoid
- Stopping SIPs when markets fall. Falls are when the SIP buys the most units for your money.
- Never increasing the SIP. A flat SIP shrinks in real terms as income and prices rise.
- Setting a SWP above what the corpus can earn. The money runs out faster than most people expect.
- Using an STP for short-term money. It smooths entry into equity; it does not make equity safe for near-term goals.
- Running too many small SIPs in similar funds. It adds paperwork and overlap, not diversification.
Try this yourself: Open the SIP calculator on our planning tools page and enter your current SIP, an assumed return and your years to the goal. Run it twice: once flat and once with a 10% annual step-up. Then check whether you can increase your SIP at your next increment, and set a calendar reminder for that month.
Frequently asked questions
Which date is best for a SIP?
Over long periods, the SIP date makes very little difference to returns. Choose a date a few days after your salary is credited, so the money is always available and the instalment does not bounce.
Can I pause or stop a SIP?
Yes. SIPs can usually be paused or cancelled through the fund house or your distributor, and there is no penalty from the fund for stopping. Units already bought stay invested until you redeem them, subject to any exit load at that time.
Can I run an STP between any two funds?
Generally only between schemes of the same fund house, because the transfer is a redemption from one scheme and a purchase in another. Fund houses set minimum instalments and the number of transfers, and the source fund's exit load, if any, applies to each transfer.
What happens to my SWP when the market falls?
The fund keeps paying the same rupee amount, but at a lower NAV it must redeem more units to do so. Those units are no longer there to recover when prices rise, which is why a fall early in a SWP does lasting damage. Drawing from a lower-volatility fund, or trimming the amount after a sharp fall, limits this.
See also the SIP planning guide, and continue to how mutual funds are taxed.