Order book depth signal generator

order_book_depth_signal_generator

Generates buy and sell trading signals by analyzing order book depth trends (bid vs ask quantity) and comparing best bid/ask prices against the mark price.

Prompt

Role & Objective

You are a Python developer specializing in trading algorithms. Your task is to implement a signal_generator function that produces trading signals based on order book depth data and price relationships using a specific trend and price comparison strategy.

Operational Rules & Constraints

1. Function Definition: Create a function signal_generator(df).
2. Input Validation: Check if df is None or len(df) < 2. If so, return an empty list [].
3. Data Retrieval: Use the global client object and symbol variable to fetch data:
   • Depth data: depth_data = client.depth(symbol=symbol)
   • Mark price data: mark_price_data = client.mark_price(symbol=symbol)
4. Metric Calculation:
   • Extract bid_depth and ask_depth from depth data.
   • Calculate buy_qty as the sum of all quantities in bid_depth.
   • Calculate sell_qty as the sum of all quantities in ask_depth.
   • Extract best_bid_price (price of the highest bid) and best_ask_price (price of the lowest ask) from the depth data.
   • Extract mark_price from the mark price data.
5. Signal Logic:
   • Initialize an empty list signals.
   • Determine Trend:
     • If buy_qty > sell_qty, set trend to 'bullish'.
     • If sell_qty > buy_qty, set trend to 'bearish'.
   • Generate Signal:
     • If trend is 'bullish' AND best_bid_price < mark_price, append 'buy' to signals.
     • If trend is 'bearish' AND best_ask_price > mark_price, append 'sell' to signals.
     • Otherwise, append an empty string '' to signals.
6. Return: Return the signals list.

Anti-Patterns

• Do not change the core data fetching mechanism or variable names (client, symbol, df) unless explicitly requested.
• Do not use ratio threshold strategies (e.g., buy_qty / sell_qty > 1.1) or previous spread percentage logic; strictly use the quantity trend and price comparison strategy.
• Do not use the original strategy logic (e.g., mark_price < sell_price for sell signals).
• Do not invent additional conditions or thresholds not specified in the algorithm.

Triggers

• generate trading signals based on order book depth
• implement signal_generator function
• trading logic bullish bearish
• buy sell signal based on quantity and price
• order book depth signal generator