# Market Data - Incremental Refresh # The initial response to a [Market Data Request ``](/trading/fix/market-data/exchange-bound-messages/market-data-request) is a full snapshot of current state followed by multiple incremental update messages. See [Examples: Market Data Responses](/trading/fix/market-data/examples/market-data-responses) for examples of bids, offers, and trade events. --- ### Fields | Tag | Name | Req | Description | | ------ | -------------------------------------------------------------------------- | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | [Standard Header](/trading/fix/overview/standard-header) | Y | [MsgType](https://www.onixs.biz/fix-dictionary/4.4/msgs_by_msg_type.html) = `X` | | 262 | [MDReqID](https://www.onixs.biz/fix-dictionary/4.4/tagNum_262.html) | Y | Unique identifier of the [Market Data Request ``](/trading/fix/market-data/exchange-bound-messages/market-data-request) this message is in response to. | | 9008 | [EventId](/trading/fix/overview/dictionary/custom-tags) | N | Event ID of the event causing the generation of the update in this message. | | 268 | [NoMDEntries](https://www.onixs.biz/fix-dictionary/4.4/tagNum_268.html) | Y | Number of entries in this message. | | ⇒ 279 | [MDUpdateAction](https://www.onixs.biz/fix-dictionary/4.4/tagNum_279.html) | Y | Type of market data update.

Valid values:
`0 = New`
`1 = Change`
`2 = Delete` | | ⇒ 269 | [MDEntryType](https://www.onixs.biz/fix-dictionary/4.4/tagNum_269.html) | Y | Type of market data entry.

Valid values:
`0 = Bid`
`1 = Offer`
`2 = Trade`
`R = MarkPrice`
`S = FundingAmount` | | ⇒ 55 | [Symbol](https://www.onixs.biz/fix-dictionary/4.4/tagNum_55.html) | N | Symbol of market data entry.

Required when [MDEntryType](https://www.onixs.biz/fix-dictionary/4.4/tagNum_269.html) is not `3 = Index Value`. | | ⇒ 270 | [MDEntryPx](https://www.onixs.biz/fix-dictionary/4.4/tagNum_270.html) | Y | Price of market data entry. | | ⇒ 271 | [MDEntrySize](https://www.onixs.biz/fix-dictionary/4.4/tagNum_271.html) | N\* | Quantity of market data entry.

\*Required when [MDEntryType](https://www.onixs.biz/fix-dictionary/4.4/tagNum_269.html) is not `3 = Index Value`. | | ⇒ 273 | [MDEntryTime](https://www.onixs.biz/fix-dictionary/4.4/tagNum_273.html) | N\* | The time that the most recent indicative price has been published. | | ⇒ 9002 | [MDEntryMakerSide](/trading/fix/overview/dictionary/custom-tags) | N\* | Custom field indicating the maker side of a trade. Enabled by sending a [Market Data Request ``](/trading/fix/market-data/exchange-bound-messages/market-data-request) with the custom field [EnableMDEntryMakerSide `<9003>`](/trading/fix/overview/dictionary/custom-tags) set to `TRUE`. Appears when [MDEntryType `<269>`](https://www.onixs.biz/fix-dictionary/4.4/tagNum_269.html) has value `2 = Trade`.

Valid values:
`1 = Buy`
`2 = Sell`

See [Examples: Showing Maker Side For Trades](/trading/fix/market-data/examples/market-data-responses). | | ⇒ 9009 | [MDEntryFundingIsRealized](/trading/fix/overview/dictionary/custom-tags) | N\* | Custom field used in [Market Data – Incremental Refresh ``](/trading/fix/market-data/client-bound-messages/market-data-incremental-refresh) MDEntry groups when [MDEntryType](https://www.onixs.biz/fix-dictionary/4.4/tagNum_269.html) had the value `S = Funding Amount` to indicate the IsRealized field of Funding Amount.

Valid values:
`Y = Yes`
`N = No` | | | [Standard Trailer](/trading/fix/overview/standard-trailer) | Y | |