Which stock has the highest weightage in Nifty Bank?
The table on this page lists every Nifty Bank stock by weight, the largest first. Weights move with share prices every day and are reset at NSE's half-yearly reviews.
How are the index points a stock contributes worked out?
A stock's contribution is its weight × its % move × the index level before the move. A stock with a 10% weight that rises 1% adds about 0.1% to Bank Nifty.
Why does a small company move the index less than a big one?
Nifty Bank is weighted by free-float market value: the share price × the shares that are freely traded. A large company with most of its shares in public hands carries far more weight, so the same % move shifts the index more.
How often does the weightage change?
Every day, as prices move. NSE also resets weights and caps at its reviews in March and September, and when a company's free float or share count changes.
Why does the total differ slightly from the index move?
NSE does not publish daily weights in a form we can use, so we work them out from each company's shares in issue, promoter holding and price. They are close but not exact, so the stocks' points add up to slightly more or less than the index moved. The difference is shown under the chart.