XIRR in SIP: Why Smart Investors Are Ditching Fixed Dates (And How to Measure It)

Most investors treat SIP like a subscription. Pick a fund, pick a date, auto-debit. Every month, same day, same amount. Done.

This works. But it's not the best you can do.

There's a smarter way to SIP — one that uses the market's own volatility to your advantage. The catch is that it creates irregular cash flows that your broker can't (or won't) calculate returns for. That's where XIRR in SIP becomes the only metric that tells you the truth.

The Old Way: Regular SIP in a Mutual Fund

A regular mutual fund SIP looks like this:

15th of every month → ₹5,000 → Nifty 50 Index Fund
No matter what the market is doing.

The logic is sound: you remove emotion from investing. You don't try to time the market. You buy consistently and average out over time.

But here's the problem: you're buying even when valuations are stretched. When the Nifty is at an all-time high and every analyst is screaming overvalued — your auto-debit still fires on the 15th. You buy at the top as faithfully as you buy at the bottom.

A fixed SIP date treats every market condition as equal. The market disagrees.

The New Way: Irregular SIP in Specific Stocks

Now consider a different approach.

Instead of a mutual fund on a fixed date, you pick a fundamentally strong stock — say a large-cap you've researched and believe in for the next 5–7 years. And instead of buying every month on the 15th, you set a simple rule:

Only buy when the stock is down 5% or more from its recent peak. Never buy just because the calendar says so.

Your buy triggers look like this:

March 2024:    No buy (market flat)
April 2024:    ₹10,000 — stock fell 7% after weak quarterly results
May 2024:      No buy (recovered)
June 2024:     ₹15,000 — global selloff, stock down 9%
July 2024:     No buy
August 2024:   No buy
September 2024: ₹8,000 — Fed rate decision triggered a 5% drop
October 2024:  No buy
November 2024: ₹20,000 — US election volatility, stock down 11%

In 9 months you bought 4 times — never on a fixed date, always at a discount.

Compare this to a fixed SIP buyer who bought 9 times, including 5 times when the stock was near its highs. You paid less per unit, on average, every single time.

Why This Strategy Works

Markets don't fall randomly. Big drops are usually caused by predictable triggers:

Global events: US Fed rate decisions, geopolitical news, oil shocks
Domestic events: RBI policy, election results, Budget announcements
Earnings disappointments: sector-wide or stock-specific quarterly misses
Panic contagion: when global markets fall 5%, Indian markets follow within hours

These events are noisy and scary — but if you're holding a fundamentally good stock, they're buying opportunities. The business hasn't changed. The price has.

A fixed SIP buyer misses these windows because the auto-debit doesn't care what the market did yesterday. A rule-based dip buyer exploits them systematically, without emotional second-guessing.

The result: a higher number of units purchased per rupee invested, compounded over years.

The Problem: How Do You Calculate Returns from Irregular SIPs?

This is where it gets tricky.

Open Zerodha Console. Go to your P&L. It shows you absolute gain/loss and a percentage. But it doesn't show your annualized return on your irregular SIP.

Open Groww. Same story — you get overall portfolio value, maybe a rough XIRR on your mutual funds, but not on your stock SIPs.

Why? Because calculating XIRR for irregular SIPs is genuinely hard.

A fixed SIP is easy to measure — same amount, same date, regular intervals. You can approximate it. But when you've invested ₹10,000 in April, ₹15,000 in June, ₹8,000 in September, and ₹20,000 in November — all on different dates, all different amounts — only one formula handles this correctly.

That formula is XIRR.

What XIRR in SIP Actually Means

XIRR — Extended Internal Rate of Return — treats each cash flow independently.

It takes your actual buy dates, actual amounts, and your current holding value, and finds the single annualized rate that explains your exact outcome.

April 12, 2024:    -₹10,000  (bought on dip)
June 3, 2024:      -₹15,000  (bought on global selloff)
September 18, 2024: -₹8,000  (bought on Fed day)
November 6, 2024:  -₹20,000  (bought on election volatility)
March 2, 2026:     +₹85,000  (current value)

XIRR = 28.4% annualized

If you had done a regular ₹5,000 monthly SIP instead, you'd have invested ₹55,000 over the same period and your XIRR would be around 19–21% — because you bought at all prices, not just the dips.

Same stock. Same holding period. Smarter entry → better XIRR.

XIRR is the only way to compare these two strategies on an apples-to-apples basis.

Why Zerodha and Groww Don't Show Your SIP XIRR

Zerodha shows you absolute P&L. Groww shows you overall portfolio return. Neither shows you XIRR on your stock purchases — especially not irregular ones.

The reason is simple: they don't have all the information they need.

Your XIRR depends on:

Every transaction date and amount (they have this)
Your net cash in and out of the account (they have this per-account, but not across brokers)
Your current holding value entered by you today (they show market value, but XIRR needs you to define the terminal point)

More importantly, your stock SIP might span multiple broker accounts. If you bought HDFC Bank across Zerodha and Fyers, no single platform sees the full picture.

So they either show you a rough approximation (which ignores timing) or nothing at all.

How to Calculate XIRR for Your SIP

The manual way (Excel)

Download your ledger from Zerodha Console → Fund Statement → All Segments
In a spreadsheet, create two columns: Date and Amount
Every buy is negative (cash out): -₹10,000
Your current portfolio value is positive (cash in today): +₹85,000
Use =XIRR(amounts_range, dates_range)

This works — but it takes 30–60 minutes the first time, and you have to redo it every time you want an updated number.

The automatic way (XIRRLedger)

XIRRLedger is built specifically for this.

Upload your broker ledger file — Zerodha CSV, Groww PDF, Fyers CSV. Enter your current holding value. XIRRLedger:

Reads your actual transaction dates and amounts from the ledger
Identifies your deposits and withdrawals automatically
Calculates your XIRR on the exact cash flows — no approximations
Compares your return against the Nifty 50 XIRR on the same cash flows

So you don't just know your SIP XIRR — you know whether your dip-buying strategy actually beat the index, or whether you would have been better off in a plain index fund.

That comparison is what makes the number meaningful.

The Verdict: Which SIP Style Is Better?

There's no universal answer — it depends on your discipline and your stock selection. But here's the honest breakdown:

	Regular SIP (Mutual Fund)	Dip-Based SIP (Specific Stocks)
Effort	Zero — fully automated	Active — requires watching + rules
Diversification	Built-in	You manage it
Average buy price	Market average	Below market average (if disciplined)
Potential XIRR	Index-level	Higher (if stock selection is right)
Risk	Index risk only	Stock-specific risk
XIRR measurability	Easy	Needs a tool like XIRRLedger

If you're willing to put in the work — follow global events, set clear dip rules, pick quality stocks you'll hold for years — a dip-based irregular SIP is worth doing. But only if you measure it correctly.

Gut feel isn't a strategy. Your XIRR is.

Ready to calculate your SIP XIRR? Upload your broker ledger and get your actual annualized return in minutes. Calculate Your XIRR →

Want to see what the report looks like? Download Sample Report →