Mutual FundsLesson 3 of 7beginner

SIP, STP and SWP

A SIP is not a product — it is a way of paying. Here is what it actually does for you, and the two related tools most people never hear about.

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A Systematic Investment Plan is an instruction: invest a fixed amount, at a fixed interval, into a chosen scheme, automatically.

That is the whole thing. A SIP is not a product, not a scheme, and not an asset class. It is a payment method. "I invest in SIP" is like saying "I shop in EMI" — the important question is what you bought.

How it works mechanically

You set an amount, a date and a scheme, and authorise an auto-debit through a NACH mandate or UPI autopay. On each date, the money is debited and units are allotted at that day's applicable NAV. Because NAV moves, you get a different number of units every month.

Rupee cost averaging

Rupee cost averaging over four SIP instalmentsFour monthly instalments of ₹6,000. Month 1 at NAV ₹100 buys 60 units; month 2 at ₹75 buys 80; month 3 at ₹60 buys 100; month 4 at ₹120 buys 50. Total 290 units for ₹24,000, an average cost of ₹82.76 per unit, below the simple average NAV of ₹88.75.₹6,000 invested each monthbar height = units bought60 unitsMonth 1NAV ₹100total 60 units80 unitsMonth 2NAV ₹75total 140 units100 unitsMonth 3NAV ₹60total 240 units50 unitsMonth 4NAV ₹120total 290 unitsInvested₹24,000Units290Avg cost₹82.76
The same ₹6,000 buys the most units in the cheapest month. Average cost ₹82.76 per unit against an average NAV of ₹88.75.

The fixed rupee amount buys more units when NAV is low and fewer when it is high. Your average cost per unit therefore ends up below the average NAV over the period.

Worked example

₹6,000 invested monthly for four months.

MonthNAVUnits bought
1₹10060.0
2₹7580.0
3₹60100.0
4₹12050.0

Total invested ₹24,000, total units 290.

Average cost = 24,000 ÷ 290 = ₹82.76

Average of the four NAVs = (100 + 75 + 60 + 120) ÷ 4 = ₹88.75

You paid less per unit than the simple average, without predicting anything.

What a SIP genuinely does — and does not do

Does: removes timing decisions, builds a habit, smooths your entry price, and makes investing possible from a monthly salary rather than a lump sum.

Does not: guarantee a profit. A SIP into a fund that falls for five years loses money. It is a method of entering, not a source of returns. The scheme you chose still determines the outcome.

SIP vs lump sum

If markets rose steadily from the day you invested, a lump sum would have done better — all the money was working from day one.

If markets fell first and recovered, the SIP does better, because much of the money bought in cheaper.

Nobody knows in advance which will happen. For most people the question is settled by circumstance: a salary arrives monthly, so investment happens monthly. If you do have a large sum and are uneasy about timing, an STP below is the standard middle path.

STP — Systematic Transfer Plan

Move a fixed amount from one scheme to another at regular intervals, usually from a low-risk debt or liquid fund into an equity fund.

Worked example

You receive ₹12 lakh. Investing it all in equity in one day feels uncomfortable.

Put ₹12 lakh in a liquid fund. Set an STP of ₹1 lakh per month into your chosen equity fund.

Over twelve months the money moves across gradually. The portion still in the liquid fund earns something in the meantime rather than sitting idle in a savings account.

SWP — Systematic Withdrawal Plan

The reverse of a SIP: redeem a fixed amount at a fixed interval, credited to your bank account.

This is the sensible way to draw a regular income from investments — far better than the IDCW option, because you control the amount and timing, and redemptions are taxed as capital gains rather than at your slab rate.

Worked example

₹40 lakh in a fund. You set an SWP of ₹25,000 per month.

Each month, enough units are redeemed to produce ₹25,000, which reaches your bank account. The remaining units stay invested and continue to participate in the market.

Practical points about SIPs

  • Any date works. There is no "best SIP date". Studies of this consistently find the difference is noise. Pick a date shortly after your salary arrives.
  • Missing a payment is not a default. The instalment simply fails; repeated failures may see the SIP cancelled, and your bank may levy a charge for the failed mandate.
  • Step-up SIP increases the amount annually by a set percentage. Since income usually rises, this keeps the investment meaningful. It is one of the highest-impact settings available and is almost always worth switching on.
  • Pause rather than stop, if cash is tight. Most platforms allow a pause of a few months, which keeps the SIP alive.
  • A SIP does not expire usefully. Many are registered for a fixed period and quietly stop. Perpetual registration avoids an accidental halt.

Key takeaways

  • A SIP is a payment method, not a product — the scheme you choose determines the result.
  • Rupee cost averaging works because falls buy more units, so stopping during a decline defeats the purpose.
  • A SIP does not guarantee profit; it removes timing decisions.
  • STP moves money gradually from a liquid fund into equity, but each instalment is a taxable redemption.
  • SWP is a better way to draw regular income than the IDCW option, on both control and tax.

Check your understanding

0 of 3 answered

  1. 1.Which month of a SIP buys the most units?
  2. 2.What is an STP typically used for?
  3. 3.Why is an SWP usually better than the IDCW option for regular income?

Frequently asked questions

Is a SIP a type of mutual fund?
No. It is simply an instruction to invest a fixed amount at a fixed interval into a scheme you have chosen.
Should I stop my SIP when the market falls?
Falling markets are when a SIP buys the most units for the same money. Stopping then removes the main benefit of the method.
Lesson 30 of 34 overall