Seeing Charts Like a Quant: When RL Teaches Vision Models to Actually Reason
Charts look harmless. A bar chart sits in a dashboard, a line chart appears in a quarterly report, a scatter plot claims there is a relationship, and everyone pretends the machine only needs to “read the image.” This is the polite fiction behind a large share of enterprise AI demos. In practice, chart understanding is not OCR with prettier fonts. A model has to identify the marks, map colors to legends, recover values, decide which numbers matter, perform arithmetic, interpret trends, and then answer the actual question rather than the easier question it secretly substituted. That last step is where many systems go from impressive to quietly expensive. ...