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Özge Karasu Özge Karasu

Curiosity leads me. I follow and write.

Distribution Modeling on Financial Time Series with MLE

20.11.2024

Goal: To gain practical experience in statistical modeling of financial data using estimation theory and visualisation.

In this project, I analysed the daily returns of the Dow Jones Industrial Average (DJIA) to model its underlying distribution using Maximum Likelihood Estimation (MLE). After computing the daily return series, I evaluated its statistical properties including skewness and kurtosis, and hypothesised suitable distribution families.

I implemented a custom log-likelihood function and optimised it using scipy.optimize.minimize to find the best-fitting parameters. The results were then compared against parameters estimated via SciPy’s .fit() method. Finally, I plotted both estimated PDFs over the histogram of returns to visually evaluate fit quality.

Key steps:

  • Computed return series from historical DJIA data
  • Analysed mean, variance, skewness, and kurtosis
  • Used MLE to fit candidate distributions
  • Compared empirical and fitted PDFs
  • Discussed model suitability based on visual and statistical evidence

Tech stack: Python, pandas, scipy, matplotlib, pandas-datareader