SIP Backtest
Glaxosmithkline Pharmaceuticals Ltd.
A ₹10,000 monthly SIP in GLAXO over the last 20 years means ₹24,00,000 paid in across 240 instalments. It would be worth ₹86,67,972 today.
Change the instalment or the holding period to run the backtest against GLAXO's own price history. Nothing here is projected from an assumed rate — every figure comes from what the share price and dividends actually did.
Every Period
Each period is a separate backtest: ₹10,000invested at the end of every month, priced at that month's adjusted close. The last instalment falls on the valuation month, so it has had no time to grow — which is exactly true of a real SIP.
12 instalments of ₹10,000 — ₹1,20,000 paid in — would be worth ₹1,51,086 today, an XIRR of 61.7%.
Same money, invested once: ₹1,43,722 (21.7% XIRR) — the SIP did better.
Same SIP into the Nifty 500: ₹1,22,790 (5.1% XIRR) — GLAXO ahead.
36 instalments of ₹10,000 — ₹3,60,000 paid in — would be worth ₹4,86,299 today, an XIRR of 21.7%.
Same money, invested once: ₹7,63,199 (29.3% XIRR) — the lump sum did better.
Same SIP into the Nifty 500: ₹3,89,924 (5.5% XIRR) — GLAXO ahead.
60 instalments of ₹10,000 — ₹6,00,000 paid in — would be worth ₹10,58,314 today, an XIRR of 23.6%.
Same money, invested once: ₹14,44,241 (19.5% XIRR) — the lump sum did better.
Same SIP into the Nifty 500: ₹7,64,087 (9.9% XIRR) — GLAXO ahead.
120 instalments of ₹10,000 — ₹12,00,000 paid in — would be worth ₹27,05,160 today, an XIRR of 15.7%.
Same money, invested once: ₹33,54,690 (10.9% XIRR) — the lump sum did better.
Same SIP into the Nifty 500: ₹22,91,828 (12.6% XIRR) — GLAXO ahead.
180 instalments of ₹10,000 — ₹18,00,000 paid in — would be worth ₹46,13,362 today, an XIRR of 11.7%.
Same money, invested once: ₹73,56,228 (9.9% XIRR) — the lump sum did better.
Same SIP into the Nifty 500: ₹49,86,478 (12.7% XIRR) — the index ahead.
240 instalments of ₹10,000 — ₹24,00,000 paid in — would be worth ₹86,67,972 today, an XIRR of 11.6%.
Same money, invested once: ₹1,93,11,753 (11.0% XIRR) — the lump sum did better.
Same SIP into the Nifty 500: ₹88,67,315 (11.8% XIRR) — the index ahead.
By Monthly Amount
Each row is a 20-year SIP in GLAXO, run at a different instalment.
| Every month | Total invested | Worth today | Gain |
|---|---|---|---|
| ₹1,000 | ₹2,40,000 | ₹8,66,797 | +₹6,26,797 |
| ₹2,000 | ₹4,80,000 | ₹17,33,594 | +₹12,53,594 |
| ₹5,000 | ₹12,00,000 | ₹43,33,986 | +₹31,33,986 |
| ₹10,000 | ₹24,00,000 | ₹86,67,972 | +₹62,67,972 |
| ₹25,000 | ₹60,00,000 | ₹2,16,69,929 | +₹1,56,69,929 |
SIP outcomes are exactly proportional to the instalment, so these rows scale from one backtest rather than five. The annualised return (XIRR) is identical for every row — only the rupee figures change.
The Metric
A SIP's return cannot honestly be quoted as a CAGR. CAGR describes one sum invested once and left alone; a SIP adds money every month, so the first instalment has been invested for 20 years and the last for a single month. Averaging those as though they were one investment overstates the result.
The correct measure is XIRR — the single annual rate that makes all 240 instalments and today's value balance. For Glaxosmithkline Pharmaceuticals Ltd. over 20 years, that rate is 11.6%.
Most Indian SIP calculators ask you to assume a rate of return — commonly 12% — and then compute forward from it. Nothing on this page is assumed: every figure comes from what the share price and dividends actually did.
SIP vs Lump Sum
₹24,00,000 put into Glaxosmithkline Pharmaceuticals Ltd. as a single lump sum at the start of the period would be worth ₹1,93,11,753 today (11.0% XIRR). The same money paid in monthly is worth ₹86,67,972.
The lump sum came out ahead. That is the usual result over a period where the price rose, because money invested earlier had longer to compound — and it is worth stating plainly rather than only showing the SIP figure.
The comparison is not really a choice for most people. A SIP invests what you earn each month; a lump sum requires having the whole amount up front. This tells you what each would have produced, not which you should have done.
SIP vs The Index
The identical 240 instalments put into the Nifty 500 on the same dates would be worth ₹88,67,315 — an XIRR of 11.8%, against ₹86,67,972 in Glaxosmithkline Pharmaceuticals Ltd.. The index is ahead over this period.
The index leg is bought month by month on exactly the same dates, not modelled at an assumed annual rate. That matters: a smooth compounded curve has no entry timing, and entry timing across many instalments is the entire subject of this page.
How This Is Calculated
Each instalment buys at that month's closing price. A real SIP buys on a fixed date that may be any trading day, so an actual outcome would differ a little in either direction.
Prices are adjusted for dividends and stock splits, so dividends are treated as reinvested. Demergers are not credited, and brokerage and taxes are not modelled.
GLAXOis in today's Nifty 500 universe. Companies that delisted or collapsed are not on this site at all — a bias worth holding in mind when reading any historical backtest.
Measured on data to 2026-08-31, from 2006-08-01. Full definitions are on our methodology page.
HELP CENTER
Everything you need to know about this page and the data presented.
Investing ₹10,000 a month in Glaxosmithkline Pharmaceuticals Ltd. for the last 20 years would have meant paying in ₹24,00,000 across 240 instalments. That holding would be worth about ₹86,67,972 today — a gain of ₹62,67,972, or 3.6× the money paid in. Every instalment is priced at that month's adjusted close, so dividends and stock splits are already counted in.
A 20 years SIP in Glaxosmithkline Pharmaceuticals Ltd. returned an XIRR of 11.6%. XIRR is the right measure for a SIP and CAGR is not: CAGR assumes one sum invested once, while a SIP puts money in every month, so each instalment is exposed for a different length of time. A 20 years SIP's final instalment has been invested for one month, not 20 years.
Over the last 20 years, no. The same ₹24,00,000 invested as a single lump sum at the start would be worth ₹1,93,11,753 today, against ₹86,67,972 for the monthly SIP. The lump sum won because the price rose over the period, so money invested earlier had longer to compound. That is the usual outcome in a rising market, and it is the honest answer rather than the flattering one. A SIP is a way of investing what you earn each month, not a technique for beating a lump sum you already have.
Over 20 years, no. The identical monthly instalments put into the Nifty 500 instead would be worth ₹88,67,315, against ₹86,67,972 in Glaxosmithkline Pharmaceuticals Ltd. — an index XIRR of 11.8%. The index leg is bought month by month on the same dates, not modelled at an assumed rate.
₹5,000 a month for 20 years adds up to ₹12,00,000 paid in, and would be worth about ₹43,33,986 today. SIP outcomes scale exactly with the instalment, so halving or doubling the monthly amount halves or doubles every rupee figure and leaves the XIRR unchanged.
₹10,000 a month for 5 years means ₹6,00,000 paid in, worth about ₹10,58,314 today — +76.4% on what went in, an XIRR of 23.6%. Shorter horizons swing far more widely than long ones, which is why this page publishes every period separately rather than picking one.
That is not a question this page answers, and we do not make recommendations. What it can tell you is exactly what a monthly SIP in Glaxosmithkline Pharmaceuticals Ltd. would have produced over every period the data covers, how that compares with the same money invested at once, and how it compares with the Nifty 500. Those are records of what happened, not forecasts — a stock that compounded well for twenty years carries no promise about the next one.
Explore Further
GLAXO overview
Price history, wealth journey and how it compares with the index.
GLAXO 20-year returns
The same period as a one-time investment, year by year.
SIP backtests for every stock
Run the same question against any company we track.
Browse every stock
1-year and 5-year returns on every row, sortable.
ReturnScreener is an educational research platform and is not a SEBI-registered investment adviser. Everything on this page is a record of what historical prices did, not a projection and not a recommendation. Past performance does not guarantee future returns. See our methodology and disclaimer.