What is machine learning in finance?
In the context of stock market analysis, machine learning is the application of mathematical models that "learn" from historical datasets to identify non-obvious patterns within noisy price action. Unlike traditional technical analysis which relies on pre-defined triggers (like a 200-day moving average), ML algorithms determine their own "features" or indicators based on what has historically preceded specific market outcomes.
We categorize these approaches into supervised and unsupervised learning. In a supervised environment, the model is trained on labeled historical data—knowing exactly what the output was. Unsupervised learning, conversely, allows the algorithm to find latent structures within data without pre-assigned goals, often revealing hidden clusterings between seemingly unrelated market sectors.