# Index Weight

Constituent weight data for major indices, spanning the CSI 300, MSCI, FTSE and other index families, giving each member stock's weight within a given rebalancing period. It is used to track index reconstitutions, estimate passive-fund indexing flows, and build benchmark or index-replication portfolios. Typically updated monthly with weights expressed as percentages; data shifts notably around effective rebalancing dates, so query by constituent period.

`GET /v2/indices/index-weight`

## Parameters

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `symbol` | string | No | Index code |
| `start_date` | string | No | Start date (YYYYMMDD) |
| `end_date` | string | No | End date (YYYYMMDD) |
| `trade_date` | string | No | Trading date YYYYMMDD (single day) |

## Response Fields

| Field | Type | Description |
| --- | --- | --- |
| `symbol` | string | Index code |
| `trade_date` | string | Effective date |
| `con_symbol` | string | Constituent stock code |
| `weight` | number | Weight in index % |

## API Example

cURL

```
curl -H "X-API-Key: YOUR_KEY" \
  "https://asharehub.com/v2/indices/index-weight?symbol=000300.SH"
```

Python SDK

```
from asharehub import AShareHub

client = AShareHub(api_key="YOUR_KEY")
df = client.index_weight(symbol="000300.SH")
print(df.head())
```

## Sample Data

returns a pandas.DataFrame

| symbol | trade_date | con_symbol | con_name | weight |
| --- | --- | --- | --- | --- |
| 000300.SH | 20260601 | 688981.SH | — | 1.0013 |
| 000300.SH | 20260601 | 688506.SH | — | 0.0665 |
| 000300.SH | 20260601 | 688472.SH | — | 0.0725 |