adjusted price meaning in stock charts

An adjusted price is a historical price that has been restated for corporate actions such as splits, bonuses and rights issues, so the chart shows one continuous series instead of an artificial cliff. The adjustment scales every earlier bar by the same factor the action applied to the share count, which is why a 1:1 bonus leaves a smooth line rather than a 50% crash. Unadjusted data keeps the raw traded prices, so every level, moving average and backtest computed across the action is calculated on a series containing an event that never happened to any holder.

a company giving existing shareholders extra shares free in proportion to their holding is called a

Bonus issue. The company capitalises its own reserves to issue the new shares, so shareholders pay nothing, the number of shares outstanding rises and the market price falls proportionally when it goes ex — a 1:1 bonus doubles the share count and roughly halves the price. A stock split produces a similar looking chart but works differently: it reduces the face value of each share rather than converting reserves into share capital.

why did my stock chart fall 50% overnight with no news

On an Indian chart the overwhelming majority of these are corporate actions shown on unadjusted data, not events — most often a bonus issue, a stock split or a demerger. Check the company’s announcements on the NSE or BSE website for that date before forming any view; if a bonus or a split went ex that day, holders lost nothing and the chart simply was not restated. A clean division by two or three is the usual giveaway that it is arithmetic rather than a business event.

difference between a bonus issue and a stock split

A bonus issue converts the company’s reserves into new shares given free to existing holders and leaves the face value of each share unchanged; a stock split cuts the face value of the existing shares into smaller pieces and touches no reserves. On the chart the two look identical — more shares, a proportionally lower price, the same total holding value — which is why both have to be adjusted for before any level or indicator on the history means anything.

does a bonus issue reduce the value of my holding

No — a bonus issue leaves the value of your holding unchanged. You simply hold more shares at a proportionally lower price, so ₹2,400 of one share becomes ₹1,200 of two after a 1:1 bonus. What it does change is the chart: an unadjusted series shows a fall you never experienced, and every price level you had marked on it now refers to the old share count.

Splits, bonuses and why your chart lies

A chart shows a stock dropping from ₹2,400 to ₹1,200 overnight. Nothing happened — it did a 1:1 bonus, and everyone who held it has twice as many shares. Whether your chart shows that as a cliff or as a continuous line is the difference between usable analysis and nonsense.

Think of it like this

Inch se centimetre

You have been recording a child's height in inches and switch to centimetres. The numbers jump, and if you plot both on one axis it looks like sudden dramatic growth. Nothing changed except the unit.

In the market

A split or bonus changes the unit. Adjusted data restates the history in the new unit so the line stays continuous. Unadjusted data plots two different units on one axis.

What gets adjusted, and what does not

Corporate action	Effect on price	Should be adjusted?
Stock split	Price falls proportionally	Yes — always
Bonus issue	Price falls proportionally	Yes — always
Rights issue	Price falls to the theoretical ex-rights price	Yes, with a factor
Dividend	Price falls by roughly the dividend	Depends — total return series adjust, price series usually do not
Demerger	Price falls by the value that left	Yes, and this one is often handled badly
Buyback	No mechanical adjustment	No

What it does to a backtest

Worked example

The same strategy on two data sets

A ten-year test on a stock with two bonuses and a split

Unadjusted dataEach looks like a 50% single-day fallThree artificial crashes

A trend system on itNone of which happened to any holderThree catastrophic "losses"

A mean-reversion system on itBuying a crash that was not a crashThree enormous "winners"

The reported resultAnd it will look plausibleWildly wrong in both directions

On adjusted dataThe strategy is actually being testedA continuous series

This is one of the more common reasons a backtest looks remarkable and cannot be reproduced live. The data was broken in a way that produced dramatic events the strategy either exploited or was destroyed by — and neither existed.

Loading interactive demo…

Work through what a split and a bonus do to price and share count. The holding value is unchanged, which is exactly why the chart must be restated.

Checking your own data

Three quick checks

1
Look for impossible single-day moves
Scan for daily changes beyond about 25% on a largecap. Almost every one is an unadjusted corporate action rather than a real event.
2
Cross-check a known action
Pick a stock you know split, and see whether the chart shows a cliff on that date. One check tells you how your provider behaves.
3
Know whether dividends are included
A price series and a total-return series differ by roughly 1–1.5% a year in India. Benchmarking against the wrong one understates your performance.

Check yourself

A chart shows a stock falling from ₹1,800 to ₹600 in one session with no news. What is the most likely explanation?

Simple bhasha mein

Inch se centimetre kar diya

Bacche ki height inch mein likh rahe the, phir centimetre mein likhna shuru kar diya — number ekdum uchhal gaya. Kuch nahi badla, sirf paimana badla. Chart pe bonus ya split ke baad bhaav aadha dikhta hai aur log samajhte hain crash ho gaya. Adjusted data hi asli line dikhata hai.

What to remember

Splits and bonuses change the unit; adjusted data restates history so the line stays continuous.
Unadjusted data breaks every level and every indicator computed across the gap.
It is a common and silent reason backtests cannot be reproduced live.
Demergers are the worst-handled action in Indian data.
Use adjusted data for analysis and your contract notes for your own returns.

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Common questions

Short, direct answers to what people ask about this topic.

adjusted price meaning in stock charts: An adjusted price is a historical price that has been restated for corporate actions such as splits, bonuses and rights issues, so the chart shows one continuous series instead of an artificial cliff. The adjustment scales every earlier bar by the same factor the action applied to the share count, which is why a 1:1 bonus leaves a smooth line rather than a 50% crash. Unadjusted data keeps the raw traded prices, so every level, moving average and backtest computed across the action is calculated on a series containing an event that never happened to any holder.
a company giving existing shareholders extra shares free in proportion to their holding is called a: Bonus issue. The company capitalises its own reserves to issue the new shares, so shareholders pay nothing, the number of shares outstanding rises and the market price falls proportionally when it goes ex — a 1:1 bonus doubles the share count and roughly halves the price. A stock split produces a similar looking chart but works differently: it reduces the face value of each share rather than converting reserves into share capital.
why did my stock chart fall 50% overnight with no news: On an Indian chart the overwhelming majority of these are corporate actions shown on unadjusted data, not events — most often a bonus issue, a stock split or a demerger. Check the company’s announcements on the NSE or BSE website for that date before forming any view; if a bonus or a split went ex that day, holders lost nothing and the chart simply was not restated. A clean division by two or three is the usual giveaway that it is arithmetic rather than a business event.
difference between a bonus issue and a stock split: A bonus issue converts the company’s reserves into new shares given free to existing holders and leaves the face value of each share unchanged; a stock split cuts the face value of the existing shares into smaller pieces and touches no reserves. On the chart the two look identical — more shares, a proportionally lower price, the same total holding value — which is why both have to be adjusted for before any level or indicator on the history means anything.
does a bonus issue reduce the value of my holding: No — a bonus issue leaves the value of your holding unchanged. You simply hold more shares at a proportionally lower price, so ₹2,400 of one share becomes ₹1,200 of two after a 1:1 bonus. What it does change is the chart: an unadjusted series shows a fall you never experienced, and every price level you had marked on it now refers to the old share count.