9. Nifty, Sensex and what “market is up” means
On the news you hear: "Sensex up 400 points, Nifty closes above a new level." But there are thousands of listed companies. How can one number tell you how "the market" did?
That number is an index.
A teacher has 50 students. She cannot discuss every student’s marks in the staff meeting. So she gives one number: the class average. If the average goes up, most students did better.
An index is like a class average for the stock market. Instead of tracking thousands of stocks, it tracks a chosen group of important companies and combines their prices into one number.
9.1 India’s two most famous indices
| Index | Run by | Companies | Started with |
|---|---|---|---|
| Nifty 50 | NSE | 50 large, actively traded companies | Base value 1000 (November 1995) |
| Sensex | BSE | 30 large, well-established companies | Base value 100 (1978-79) |
There are many more: Nifty Bank (banking stocks – traders call it "Bank Nifty"), Nifty IT, Nifty Pharma, Nifty Midcap, Nifty Smallcap, and so on.
9.2 Big companies have a bigger say
Nifty and Sensex are not simple averages. They are weighted by free-float market cap – roughly, the value of shares that are actually available for the public to trade. So a giant bank has much more weight in the index than a smaller company.
Try it:
This is why on some days, the Nifty is up even though most stocks fell. A few heavyweight companies went up strongly and pulled the index up.
9.3 Points vs percentage
"Sensex up 400 points" sounds big. But when the Sensex is at a high level, 400 points may be less than 1%. Always think in percentage, not points.
9.4 Why indices matter to you
- They show the mood of the market. Most stocks tend to move with the broad market.
- They are a benchmark. If your portfolio grew 8% while Nifty grew 15%, you underperformed.
- You can invest in them directly through index funds and ETFs.
- Traders trade them. Nifty and Bank Nifty are among the most traded instruments in India through futures and options.
I have tracked Nifty and Bank Nifty charts for years. One habit I recommend: before you look at any stock, open the Nifty chart first. If the overall market is falling hard, most stocks will struggle, however good they look. Pehle market, phir stock.
The index is weighted by market cap. A few giants can outweigh many smaller falling stocks.
Points depend on the index level. Percentage tells the real size of the move.
- An index tracks a group of stocks to show how the market is doing – like a class average.
- Nifty 50 (NSE, 50 stocks) and Sensex (BSE, 30 stocks) are the main ones. There are sector indices like Nifty Bank.
- Indices are weighted by free-float market cap, so big companies move them more.
- Judge moves in percentage, not points. Check the index before analysing any stock.
- Ek line mein: Index matlab market ka class average – bade companies zyada hilaate hain, isliye points nahi, percentage dekho.