> ## Documentation Index
> Fetch the complete documentation index at: https://data.birdeye.so/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# 2026.08.30 - Add Market Cap Chart Mode to WebSocket OHLCV Subscriptions

> Added release note.

# 2026.08.30 - Add Market Cap Chart Mode to WebSocket OHLCV Subscriptions

Expand WebSocket OHLCV subscriptions with a new `chartBy` selector so clients can receive OHLCV candles by token price or by market cap.

**WebSocket - Subscribe OHLCV**

[Token/Pair OHLCV](../websockets/subscribe-price-ohlcv)

### Features

* Add `chartBy` to OHLCV subscriptions
* Support `price` and `mcap` as valid `chartBy` values
* Default `chartBy` to `price` when omitted
* Support market cap OHLCV output for token subscriptions on Solana
* Fall back to price-based OHLCV if token supply is unavailable
* Keep existing OHLCV subscription behavior unchanged for clients that do not send `chartBy`

#### Parameters

| Parameter | Type   | Required | Default | Description                                                                                                                               |
| --------- | ------ | -------- | ------- | ----------------------------------------------------------------------------------------------------------------------------------------- |
| `chartBy` | string | No       | `price` | Select OHLCV display mode: `price` or `mcap`. `mcap` applies to token OHLCV on Solana and falls back to `price` if supply is unavailable. |

#### Compatibility Note

* Existing clients continue receiving price-based OHLCV data without any request changes
* `chartBy=mcap` is only applicable to token OHLCV on Solana
* Unsupported `chartBy` values are rejected