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

> ## Agent Instructions
> API requests use the base URL https://api.unusualwhales.com and require a bearer token in the `Authorization` header (`Authorization: Bearer <API_KEY>`). Create and manage API tokens at https://unusualwhales.com/dashboard/api.
> For live market data inside an AI tool, use the Unusual Whales MCP server at https://unusualwhales.com/public-api/mcp.
> Instructions for agents using Unusual Whales tools: https://unusualwhales.com/skill.md

# MultiLegSpreadLeg

> One leg of a spread.

Message
fields**12**
used by[MultiLegSpread](/docs/kafka/types/MultiLegSpread.md)

**Proto definition**

```protobuf schema.proto theme={null}
message MultiLegSpreadLeg {
  int32 option_symbol_id = 1;
  string option_symbol = 2;
  OptionTradeSide side = 3;
  int32 size = 4;
  string price = 5;
  string delta = 6;
  string theta = 7;
  string ewma_nbbo_bid = 8;
  string ewma_nbbo_ask = 9;
  string premium = 10;
  int64 volume = 11;
  int32 open_interest = 12;
}
```

## Fields

The number on the right of each row is the protobuf field number.

option\_symbol\_id
int32
1

The option chain's id.

option\_symbol
string
2

The option symbol the leg trades.

side
[OptionTradeSide](/docs/kafka/types/OptionTradeSide.md)
3

Whether the leg was bought (ask) or sold (bid).

size
int32
4

Total contracts traded on this leg.

price
string
5

Average fill price for the leg.

delta
string
6

The leg's delta.

theta
string
7

The leg's theta.

ewma\_nbbo\_bid
string
8

The leg's NBBO bid.

ewma\_nbbo\_ask
string
9

The leg's NBBO ask.

premium
string
10

Total premium for the leg.

volume
int64
11

The chain's volume.

open\_interest
int32
12

The chain's open interest.