Interactive Brokers TWS API message code
Interactive Brokers TWS API message code: 309 (max market depth requests)
The error, as text you can copy
309- Kind
- TWS API message code
- Where you meet it
- In the TWS API, not in the Web API and not in an HTTP status
What does 309 (max market depth requests) mean on the Interactive Brokers API?
Interactive Brokers lists TWS API error code 309 with a text that begins "Max number (3) of market depth requests has been reached." (the vendor's wording). The text says TWS limits users to 3 distinct market depth requests and that the same restriction applies to API clients, which may still make more than one request for the same security. The vendor's note says the maximum market depth requests were exceeded and refers to its market data line documentation.
Risk warning: CFDs and spread bets are complex instruments and come with a high risk of losing money rapidly due to leverage. You can lose money on these products, and each provider publishes its own loss figure under FCA rules. You should consider whether you understand how they work and whether you can afford to take the high risk of losing your money. Automated and API trading can amplify losses through bugs, connectivity failures and runaway orders.
How do I fix 309 (max market depth requests)?
The message states the limit: at most 3 distinct market depth requests. Cancel a market depth request you no longer need before making another.