How to Check ETH Market Depth on OKX?

Understanding Market Depth Fundamentals

1. Market depth reflects the real-time liquidity of an asset by displaying all pending buy and sell orders at various price levels.

2. On OKX, ETH-USDT order book data is structured into bid (buy) and ask (sell) sides, each showing cumulative volume per price tier.

3. The depth chart visually represents how much ETH can be bought or sold without significantly moving the market price.

4. A deep order book indicates strong liquidity, reducing slippage risk during large executions.

5. Thin depth near the best bid/ask often signals potential volatility or low participation at critical price zones.

Accessing Order Book Data via python-okx

1. Import the MarketData module: from okx.MarketData import MarketAPI.

2. Initialize the client without authentication since public market data does not require API keys.

3. Call get_orderbook(instId='ETH-USDT', sz=40) to retrieve 40 levels from both bid and ask sides.

4. The response contains arrays labeled 'bids' and 'asks', each entry formatted as [price, size, number_of_orders].

5. Parsing logic must handle string-type price and size fields, converting them to float for quantitative analysis.

Interpreting Real-Time Depth Metrics

1. Bid-ask spread calculation uses the top-level values: float(asks0) - float(bids0).

2. Cumulative bid volume within 0.5% of mid-price reveals short-term buying pressure intensity.

3. Asks stacking heavily below current last price may indicate imminent downward momentum if triggered.

4. Sudden disappearance of large limit orders at key support/resistance levels often precedes breakout moves.

5. Imbalance ratio—defined as total bid volume divided by total ask volume over identical price ranges—serves as a sentiment proxy.

WebSocket Integration for Live Updates

1. Use okx.websocket.PublicChannel to subscribe to the 'books5' or 'books-l2-tbt' channel for ETH-USDT.

2. 'books5' delivers top five levels with delta updates; 'books-l2-tbt' provides full Level 2 updates in tick-by-tick mode.

3. Each message includes sequence numbers enabling strict ordering and detection of missed packets.

4. Local order book reconstruction requires applying deltas incrementally while validating checksums against snapshot responses.

5. Reconnection logic must fetch fresh snapshots upon session restoration to maintain state consistency.

Frequently Asked Questions

Q: Does OKX provide historical depth snapshots?A: No. OKX does not archive order book states. Developers must log WebSocket messages or poll REST endpoints at defined intervals to build custom history.

Q: Can I fetch depth for ETH perpetual contracts using the same method?A: Yes. Replace 'ETH-USDT' with 'ETH-USDT-SWAP' in the instId parameter to access perpetual contract depth data.

Q: Why do some depth levels show zero volume despite visible price points?A: Those entries represent aggregated price tiers where no active limit orders exist; they appear due to exchange-side aggregation logic rather than actual resting orders.

Q: Is there a rate limit on order book REST requests?A: Public endpoints are limited to five requests per second per IP address. Exceeding this triggers HTTP 429 responses until the window resets.