> For the complete documentation index, see [llms.txt](https://docs.cryptostats.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cryptostats.dev/streaming/arbitrage.md).

# Arbitrage

You can see the current best bid and best ask for any cryptocurrency pair that trades vs USD, e.g. BTCUSD, ETHUSD, across every covered exchange that allows trading in that pair.

The subscription also returns the current bid-ask spread on that exchange, and the amount currently at the best bid and best ask.

This allows you to determine arbitrage possibilities, find the exchange with the best spread and see how an asset is trading on different exchanges. You can also use the spread of different instruments and exchanges to calibrate market-making strategies and execution algorithms.

Subscribe using the name of the currency and the instrument type (spot or perpetual).

```python
ws.send({action: 'subscribe', channel: ['BTCUSD spot'.arbitrage]})
```

### Arbitrage Returns

The return from a subscription looks like the below:

```python
{
   "exchange":"deribit",
   "bestBidPrice":57339,
   "bestAskPrice":57339.5,
   "bestBidAmount":16010,
   "bestAskAmount":159120,
   "spread":0.5
}{
   "exchange":"delta",
   "bestBidPrice":57354.5,
   "bestAskPrice":57363,
   "bestBidAmount":18641,
   "bestAskAmount":11071,
   "spread":8.5
}{
   "exchange":"bybit",
   "bestBidPrice":57339.5,
   "bestAskPrice":57340,
   "bestBidAmount":6227067,
   "bestAskAmount":8095652,
   "spread":0.5
}{
   "exchange":"bybit",
   "bestBidPrice":57339.5,
   "bestAskPrice":57340,
   "bestBidAmount":6267589,
   "bestAskAmount":8098152,
   "spread":0.5
}{
   "exchange":"phemex",
   "bestBidPrice":57337,
   "bestAskPrice":57337.5,
   "bestBidAmount":763435,
   "bestAskAmount":1703166,
   "spread":0.5
}{
   "exchange":"deribit",
   "bestBidPrice":57334,
   "bestAskPrice":57336.5,
   "bestBidAmount":10,
   "bestAskAmount":8000,
   "spread":2.5
}{
   "exchange":"huobi-dm-swap",
   "bestBidPrice":57329.8,
   "bestAskPrice":57329.9,
   "bestBidAmount":13171,
   "bestAskAmount":3946,
   "spread":0.09999999999854481
}{
   "exchange":"bybit",
   "bestBidPrice":57339.5,
   "bestAskPrice":57340,
   "bestBidAmount":5869163,
   "bestAskAmount":8273993,
   "spread":0.5
}{
   "exchange":"coinflex",
   "bestBidPrice":57349,
   "bestAskPrice":57359,
   "bestBidAmount":0.014,
   "bestAskAmount":0.035,
   "spread":10
}{
   "exchange":"phemex",
   "bestBidPrice":57337,
   "bestAskPrice":57337.5,
   "bestBidAmount":642897,
   "bestAskAmount":1766022,
   "spread":0.5
}{
   "exchange":"delta",
   "bestBidPrice":57339,
   "bestAskPrice":57347.5,
   "bestBidAmount":18641,
   "bestAskAmount":11071,
   "spread":8.5
}{
   "exchange":"gate-io-futures",
   "bestBidPrice":57358.5,
   "bestAskPrice":57358.6,
   "bestBidAmount":221655,
   "bestAskAmount":6508,
   "spread":0.09999999999854481
}
```