"Order sent" — but the broker never took it

Fri, 09 Oct 2026 00:00:00 +0000

What went wrong

Our bot sent its usual alert: “order sent”. We relaxed. Later we found that the broker had rejected the order. The position the bot believed it had opened didn’t exist.

The bot was reporting what it had tried to do, not what had actually happened. It called the broker’s order API and announced success, without checking the broker’s reply.

Lots or units? The same order, ten times the size

Fri, 09 Oct 2026 00:00:00 +0000

What went wrong

We run the same strategies across accounts at more than one broker. For a commodity future with a lot size of 10, our code sent an order with a quantity of 10. One broker placed 1 lot (10 units). The other placed 10 lots (100 units). Same code, same contract, same number: ten times the position.

Orders on The Algo Bench

"Order sent" — but the broker never took it

What went wrong

Lots or units? The same order, ten times the size

What went wrong