To fetch **MTM (Mark-to-Market)** data using the **Interactive Brokers (IBKR) API**, you'll typically use the **TWS API (Trader Workstation API)** or the IBKR Gateway. Here’s a general workflow:
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### Steps to Get MTM:
1. **Set Up IBKR API**:
- Ensure TWS or IBKR Gateway is running and API access is enabled.
- Install the IBKR API SDK (Python ib_insync is recommended for simplicity).

2. **Fetch Positions**:
- Use the API to fetch open positions using the reqPositions() function.

3. **Fetch Market Data**:
- Use the reqMktData() function to get the latest market prices for the instruments in your positions.

4. **Calculate MTM**:
- MTM = (Current Market Price - Average Cost) × Quantity
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### Python Example Using ib_insync:

1. **Install the SDK**:

bash

 pip install ib_insync

 

2. **Code**:
python
from ib_insync import IB

# Connect to TWS or IBKR Gateway
ib = IB()
ib.connect('127.0.0.1', 7497, clientId=1) # Adjust port if using IBKR Gateway

# Fetch Positions
positions = ib.positions()

# Calculate MTM
total_mtm = 0
for pos in positions:
contract = pos.contract
avg_cost = pos.avgCost
quantity = pos.position

# Fetch Market Price
market_data = ib.reqMktData(contract, '', False, False)
ib.sleep(2) # Wait for market data to be retrieved
current_price = market_data.last if market_data.last else market_data.close

# Calculate MTM
mtm = (current_price - avg_cost) * quantity
total_mtm += mtm

print(f"Symbol: {contract.localSymbol}, MTM: {mtm:.2f}")

print(f"Total MTM: {total_mtm:.2f}")

# Disconnect
ib.disconnect()

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### Key Points:
1. **Port & Client ID**:
- TWS default port: 7497 (for live) or 7496 (for paper trading).
- Use unique clientId if running multiple connections.

2. **API Access**:
- Enable API settings in TWS under *File > Global Configuration > API > Settings*.
- Set trusted IPs and ensure the API is active.

3. **Handling Market Data**:
- The example uses ib.reqMktData()` for the latest price. Adjust based on your subscription or latency requirements.

4. **Error Handling**:
- Add error handling for network issues, invalid symbols, or missing market data.

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This code will calculate MTM for all open positions.