Source: https://databento.com/docs/datasets/iexg-tops


# IEX TOPS

**Dataset ID**: [IEXG.TOPS]($PLATFORM_HOSTNAME/catalog/us-equities#IEXG.TOPS)

IEX disseminates top-of-book and trade information for its US equities exchange through their IEX TOPS feed over the IEX-TP v1 protocol, which Databento receives over UDP multicast in our NY4 data center.

PDF specifications are available through IEX's website for [IEX TOPS](https://www.iexexchange.io/documents/tops-v1-66) and [IEX-TP v1](https://www.iexexchange.io/documents/iex-tp-v1).

> **Info**
>
> The Databento team is currently working on this article.

### Symbol convention

Raw symbols in this dataset use the **Nasdaq** convention (e.g. `BRK.B`, `AAC+`).
See [CMS vs. Nasdaq symbology](https://databento.com/docs/conventions/symbology.md#raw-symbol) for the per-dataset convention map.

### Timestamps

IEX TOPS messages received by Databento will generally include two timestamps with nanosecond precision.
As with all of our datasets, we also collect a `ts_recv` timestamp when the packet was received by our capture server.

| Databento Field | IEX Field | Description |
| `ts_recv` | N/A | The capture-server-received timestamp. |
| `ts_event` | Timestamp (TOPS) | The matching-engine-received timestamp. |
| `ts_in_delta` | Send Time (TP) | The matching-engine-sending timestamp. |

More details about our timestamps are available in our [timestamping guide](https://databento.com/docs/architecture/timestamping-guide.md).

### Flags normalization

The `F_PUBLISHER_SPECIFIC` flag provides no additional meaning in this dataset and can be safely ignored.