Diagnosing a Missing Score Column in a LightGBM Ranking Pipeline

Summary

This forum post documents a BigQuant workflow in which LightGBM finishes running, but the subsequent score-to-position step fails because its query orders predictions by a column named score that is absent from the input dataset. The error identifies the available fields as instrument and prediction. The post contrasts this behavior with a StockRanker model that does not trigger the same error, and includes a large workflow covering feature construction, model fitting, prediction, portfolio selection, and trading.

The reported traceback points to a mismatch between the prediction field produced by this LightGBM module and the field expected by the position-sizing module. This makes output-column inspection and consistent field naming a useful debugging direction, though the post does not include a confirmed fix or follow-up resolution. It offers no evidence about model quality or trading performance; its value is as a troubleshooting example for handling model outputs in a quantitative pipeline.

Key ideas

• The workflow fails when score-to-position orders by score but the LightGBM output contains prediction instead.
• The error occurs after the LightGBM module completes, in the downstream portfolio-position step.
• The traceback exposes the actual available fields, which helps locate the column-name mismatch.
• The post reports that StockRanker behaves differently but does not establish why.
• No fix, model evaluation, or trading performance results are provided.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.