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

# Symbols

> One naming convention across every venue.

Whatever a venue calls an instrument internally — `BTCUSDT`, `BTC-USD`, `XBTUSD`, `tBTCUSD` — you write it one way and SORY translates. That is what makes adding a venue one string rather than a mapping table you maintain.

## Spot

`BASE/QUOTE`

```python theme={"dark"}
"BTC/USDT"   # BTC spot, quoted in USDT
"ETH/USD"    # ETH spot, quoted in USD
"ETH/BTC"    # ETH spot, quoted in BTC
```

## Perpetual swaps

`BASE/QUOTE:SETTLE` — the part after the colon is the settlement currency, which is what separates a linear contract from an inverse one.

```python theme={"dark"}
"BTC/USDT:USDT"   # linear:  quoted in USDT, settled in USDT
"BTC/USD:BTC"     # inverse: quoted in USD, settled in BTC
```

<Warning>
  `BTC/USD` and `BTC/USD:USD` are different instruments — the first is spot, the second a perpetual. This is the most common configuration mistake. SORY tells you at startup if a symbol is not listed on a venue.
</Warning>

## Products

| Product                         | Supported            |
| ------------------------------- | -------------------- |
| Spot                            | Yes                  |
| Spot margin, including shorting | [Per venue](/venues) |
| Perpetual swaps                 | Yes                  |
| Dated futures                   | No                   |
| Options                         | No                   |

Dated futures and options need expiry and strike handling throughout routing. SORY stays small instead.

## Not every venue lists every pair

That is fine — SORY subscribes where the symbol exists and excludes the rest, explicitly:

```python theme={"dark"}
sory.book("BTC/USDT").venues     # ('binance', 'bybit', 'okx')
sory.book("BTC/USDT").excluded   # {'kraken': 'symbol not listed on this venue'}
```

Nothing is silently missing. If a venue is not contributing, the book says so and why.