Why forecasting stocks is hard
Forecasting works where the data have structure. Stocks have weak structure. ⸻ Weak patterns Trends break on news. Seasonality is minimal. Cycles are unstable. Autocorrelations are low. The data behave like noise. ⸻ The main drivers are outside the time series Future prices depend on what is not in the history: regulator decisions, earnings, liquidity, events, market sentiment. The time series does not contain causes. ⸻ Predictors are unknown or unpredictable It’s not enough to know the variables — you must forecast them. With stocks, that’s hard or impossible. ...