What is the break-even NAV of a SIP investment?

The break-even NAV of a SIP is its average unit cost — the total amount invested divided by the total units bought. In the example, ₹3,50,000 across 4,621 units gives a break-even NAV of ₹75.74, well below the lump sum's break-even NAV of ₹100. A lower break-even means the portfolio turns profitable before the market has fully recovered.

Why is a market crash called a buying opportunity for SIP investors?

Because each instalment during the fall buys units at a NAV below the starting NAV. Those extra units are held at a discounted cost, so when the market recovers and they are priced higher, they lift the portfolio value. The goal during a crash is unit accumulation at discounted NAVs, not immediate profit.

Does a lump sum ever beat a SIP?

Yes. Lump sum investments do better in rising markets. The difficulty is that it is very hard for any investor to judge the current market trend in advance. Without that timing information, the priority shifts to avoiding a catastrophic drop in a lump sum portfolio caused by a market crash.

Is SIP Better than Lump Sum in a Falling Market?

Q: Is SIP better than lump sum in a falling market?

In a falling market, a SIP typically holds up better. In the worked example, ₹3 lakh invested as a lump sum at a ₹100 NAV buys 3,000 units and shows a 35% paper loss when the NAV drops to ₹65. The same ₹3 lakh invested as ₹50,000 monthly across the fall buys 3,996 units — 996 extra units for the same cash — and the paper loss is only 13.42%.

Pranjal is very happy to get a work bonus of ₹3 lakh this year. She is considering investing this idle cash somewhere, but is unsure if she should choose a Lump-sum or SIP investment. A market crash of 15% in NIFTY is happening at the moment, and she has also heard that crashes are ‘buying opportunities’. But she has never seen the actual mechanism behind this claim, and is hesitant to make rushed decisions with her money. She needs to decide soon, as her hard-earned money is slowly losing out to inflation in a savings account.

To help Pranjal and all the other undecided investors, here are the advantages that SIPs offer and a step-by-step math of why a market crash works so well with a SIP investment strategy.

Market Timing Trap

It is widely known that lump sum investments do better in rising markets. But it is very difficult for any investor to judge the current market trend. In the absence of this timing information, the priority shifts to avoiding the catastrophic crash of a lump sum investment portfolio caused by a market crash.

Unit Accumulation at "Discounted" NAVs: Smaller Paper Losses during a Market Crash

The main goal of using SIP investments during market crashes is not just to make a profit, but also to accumulate units at prices cheaper than the starting NAV. So when the market recovers, these excess units, now priced higher, can increase the portfolio value.

For example,

If Pranjal chooses a lump sum investment, with a starting NAV of ₹100,

Starting NAV = ₹100
Starting Portfolio Value = ₹3,00,000
Total Units Bought = ₹3 lakh / ₹100 per unit = 3,000 units
Ending NAV (assuming) = ₹65
Ending Portfolio Value, at 6 months = ₹65 per unit × 3,000 units = ₹1,95,000
Paper Loss in Portfolio Value = ₹1,05,000 = 35% Loss

Instead, if she chooses a SIP investment of ₹50,000 monthly for 6 months, and with a starting NAV of ₹100,

Month	Market Phase	Fund NAV (₹)	SIP Units Bought
1	Crash Begins	₹100	500
2	Slide Continues	₹90	555
3	Deepening Dip	₹80	625
4	Panic Phase	₹70	714
5	Market Bottom	₹60	833
6	Stabilizing	₹65	769

Starting NAV = ₹100
Monthly investment = ₹50,000
Starting Portfolio Value of total invested = ₹3,00,000
Total Units Bought = 3,996 units
Ending NAV (assuming) = ₹65
Ending Portfolio Value, at 6 months = ₹65 per unit × 3,996 units = ₹2,59,740
Paper Loss in Portfolio Value = ₹40,260 = 13.42% Loss

Choosing the SIP plan, Pranjal accumulated 996 extra units for the same cash. And even the portfolio value drop (13.42% Loss) in the crash was much less compared to that observed in a lump sum investment.

So she was not only able to accumulate more fund units, but she also saved her portfolio from the worst effects of the market crash.

Lower Break-Even NAV: Turning Paper Losses into Profit before Full Market Recovery

Even though the portfolio value decreased during the market crash, causing a paper loss, the subsequent value gain during recovery is much faster.

Continuing with Pranjal’s example, suppose the market starts to recover, and the current NAV sits at ₹80 the following month.

If the lump sum investment was chosen,

Starting NAV = ₹100
Starting Portfolio Value = ₹3,00,000
Total Units Bought = ₹3 lakh / ₹100 per unit = 3,000 units
Ending NAV (assuming) = ₹80
Ending Portfolio Value, at 7 months = ₹80 per unit × 3,000 units = ₹2,40,000
Paper Loss in Portfolio Value = ₹60,000 = 20% Loss

Instead, in a SIP investment,

Month	Market Phase	Fund NAV (₹)	SIP Units Bought
7	Recovery continues	₹80	625

Starting NAV = ₹100
Monthly investment = ₹50,000
Starting Portfolio Value of total invested = ₹3,50,000
Total Units Bought = 4,621 units
Ending NAV (assuming) = ₹80
Ending Portfolio Value, at 7 months = ₹80 per unit × 4,621 units = ₹3,69,680
Paper Profit in Portfolio Value = ₹19,680 = 5.62% Profit

The fund with the SIP strategy has already turned a profit (5.62%) on the investment, whereas the lump sum strategy is still recovering from the loss of a market crash.

The lump sum investment would continue to experience a paper loss until the now-recovering NAV matches the original starting NAV of the bought fund. This is called the Break-Even NAV, crossing which the fund starts to make a profit again after the market crash.

Pranjal’s investments were all bought at a starting NAV of ₹100,

Now with a lump sum investment,
Break-Even NAV = ₹100

But with the SIP option,
Break-Even NAV = Avg. Unit Cost
= Starting Portfolio Value of Total Invested / Total Units bought
= ₹3,50,000 / 4,621 units = ₹75.74

Since the break-even NAV value is much lower for a SIP investment plan, the investor's portfolio starts making a profit before the market has fully recovered. A partial recovery is enough.

And there is no guarantee when the market will turn around. But when they do, the SIP's lower average cost and its paper losses stay smaller than a lump sum's throughout the decline.

Why SIPfund?

We are an AMFI-registered mutual fund distributor, assisting investors with their goal planning, evidence-based fund selection, and guidance during market fluctuations.

Our SIPfund App makes it very easy for investors to choose funds that match their goals with an easy fund selection flow and a comprehensive investment review dashboard. The investor's funds are also safely transmitted to the AMCs through NSE’s secure platforms.

The Final Verdict

If Pranjal dumps her entire ₹3 Lakh bonus at once, it creates the risk of heavy losses if the market drops further. But leaving it in savings guarantees that it loses to inflation. By using SIP investments, Pranjal turns market volatility to her advantage.

You can get monthly fund analysis and recommendations matching your investment goal on the SIPfund Investment App (iOS or Android). You can also call us at 95133 55661 for any other questions.

Disclaimer: The information provided in this article is for educational purposes only and does not constitute investment advice or a recommendation to buy or sell any mutual fund. Mutual Fund investments are subject to market risks, read all scheme-related documents carefully.