A series is a short code NSE attaches to every listed security to say what kind of instrument it is and how it can be traded. EQ is the normal equity series where both intraday and delivery trades are allowed; BE and BZ are trade-to-trade series where every single trade must be settled by delivery.
Why do exchanges use series at all?
An exchange lists thousands of instruments, ordinary shares, shares under surveillance, debt securities, government bonds and more. Rather than write a rulebook per stock, NSE groups securities into series, and the rules follow the series. When you look up a stock and see EQ or BE after its symbol, that suffix is telling you which rulebook applies to your order.
Say Vikram searches for the fictional Sundar Textiles and the result shows SUNDARTEX-EQ. The EQ tells him this is a regular equity listing: he can trade it as Delivery or Intraday, and both limit and market orders are available.
What does the EQ series mean?
EQ is the default series for equity shares on NSE. In this series:
- Delivery trades work normally. Buy, hold the shares in demat, sell whenever you choose.
- Intraday is allowed. You can buy and sell within the same day, and your buys and sells net off against each other.
- Both limit and market orders are accepted.
Most of the well-traded stocks you see day to day sit in EQ.
What are the BE and BZ series?
BE and BZ mark stocks the exchange has moved into the trade-to-trade (T2T) segment, usually under its surveillance framework, for example after unusual price moves or other risk signals. The full mechanics are covered in what is a Trade-to-Trade (T2T) stock?, but the short version: every trade must end in delivery. There is no intraday netting, so you cannot buy and sell the same shares within a day.
BZ is also a trade-to-trade series, applied to stocks with additional concerns, typically companies flagged for non-compliance with listing requirements or under stricter surveillance. Trading-wise it behaves like BE (delivery only), but the flag itself signals the exchange sees elevated risk.
There is a second practical restriction: for trade-to-trade and debt-category instruments, market orders are typically not accepted. You must place a limit order. The reasons are covered in why are market orders blocked for trade-to-trade and debt category instruments?.
| Series | What it means | Intraday? | Market orders? |
|---|---|---|---|
| EQ | Normal equity segment | Allowed | Allowed |
| BE | Trade-to-trade (compulsory delivery) | Not allowed | Typically blocked; use limit orders |
| BZ | Trade-to-trade with added surveillance/compliance flags | Not allowed | Typically blocked; use limit orders |
Can a stock's series change?
Yes. The exchange reviews the trade-to-trade list periodically, so a stock can move from EQ to BE and later back to EQ. If a stock you traded freely last month suddenly rejects your intraday order, check its series. A shift to BE or BZ is the usual explanation. You will also come across other series on NSE, such as those used for SME-platform stocks and debt instruments; each carries its own rules, and the suffix is always your first clue.
Things to keep in mind
- Check the series suffix before you place an order. It decides whether intraday and market orders are even possible.
- A BE or BZ tag is a caution light: the exchange has put the stock under compulsory delivery, often because of unusual activity.
- Delivery-only means you need the full trade value upfront; there is no intraday leverage in BE or BZ.
- A stock's series can change at periodic reviews, so yesterday's EQ stock may be today's BE stock, and vice versa.
Read next
What is a Trade-to-Trade (T2T) stock, and how can I trade it? — The BE and BZ series you just met are trade-to-trade. Here is what that restriction means in practice.