Two histories, both true.

Why a second history has to exist

01.07.05 established the problem: after a bonus, a split or a rights issue, the prices either side of the ex-date are in different units. Bharat Foods at ₹500 becomes ₹250 the morning after a one-for-one bonus, and nobody has lost anything — there are simply twice as many shares.

A chart drawn from the traded prices shows that as a fall of half. Every return, average and level crossing the date is then wrong, not because the data is false but because it is being read as though the units never changed.

So data providers keep a second version. An adjusted history divides every price before the ex-date by the same factor — 2 for a one-for-one bonus or a ₹10 to ₹5 split, 1.5 for a one-for-two bonus — so the whole series is expressed in today's units and the step disappears.

Both series are now published. The raw one says what changed hands. The adjusted one says what a holder earned. Neither is the truth on its own.

Which one your question needs

Adjusted, for anything about return. What did a holder make over five years; how did this company do against an index; what was the drawdown. These are questions about a holding, and a holding passed through the corporate action.

Raw, for anything about a price that was actually paid. What did it cost on the day you bought; what level did a headline quote; where was the high before the split. These are questions about transactions, and transactions happened in the units of their day.

The rule follows the chapter before it: the question picks the setting. What is new here is that getting it wrong produces no error message and no odd-looking chart. Both series are smooth, plausible and internally consistent.

The parts of this nobody mentions

Volume adjusts too, in the opposite direction. If prices before the ex-date are divided by 5, the share counts are multiplied by 5, so a historical volume figure is not the number of shares that traded that day either.

Dividends are optional. A bonus or split must be adjusted for or the series is broken. A dividend need not be: 01.07.05 put the factor for Bharat Foods' hypothetical ₹4 dividend at about 1.008. Some providers apply it and some do not, and this is where two respectable sources disagree most often about the same company.

A buyback has no factor at all. Shares are extinguished and the price is not restated, so nothing in the history moves.

Adjusted prices are rewritten every time there is a new action. The ₹300 on your chart today becomes ₹150 after the next one-for-one bonus. An adjusted history is not a fixed record; it is a view recalculated from the present backwards.

That is adjustment done correctly. The next lesson is about the three ways it is done incorrectly — and how each one looks, because each leaves a mark you can learn to spot.