Book Image

Python for Finance Cookbook

By : Eryk Lewinson
Book Image

Python for Finance Cookbook

By: Eryk Lewinson

Overview of this book

Python is one of the most popular programming languages used in the financial industry, with a huge set of accompanying libraries. In this book, you'll cover different ways of downloading financial data and preparing it for modeling. You'll calculate popular indicators used in technical analysis, such as Bollinger Bands, MACD, RSI, and backtest automatic trading strategies. Next, you'll cover time series analysis and models, such as exponential smoothing, ARIMA, and GARCH (including multivariate specifications), before exploring the popular CAPM and the Fama-French three-factor model. You'll then discover how to optimize asset allocation and use Monte Carlo simulations for tasks such as calculating the price of American options and estimating the Value at Risk (VaR). In later chapters, you'll work through an entire data science project in the financial domain. You'll also learn how to solve the credit card fraud and default problems using advanced classifiers such as random forest, XGBoost, LightGBM, and stacked models. You'll then be able to tune the hyperparameters of the models and handle class imbalance. Finally, you'll focus on learning how to use deep learning (PyTorch) for approaching financial tasks. By the end of this book, you’ll have learned how to effectively analyze financial data using a recipe-based approach.
Table of Contents (12 chapters)

Estimating value-at-risk using Monte Carlo

Value-at-risk is a very important financial metric that measures the risk associated with a position, portfolio, and so on. It is commonly abbreviated to VaR, not to be confused with Vector Autoregression. VaR reports the worst expected loss at a given level of confidence over a certain horizon under normal market conditions. The easiest way to understand it is by looking at an example. Let's say that the 1-day 95% VaR of our portfolio is $100. This means that 95% of the time (under normal market conditions), we will not lose more than $100 by holding our portfolio over one day.

It is common to present the loss given by VaR as a positive (absolute) value. That is why in this example, a VaR of $100 means losing no more than $100.

There are several ways to calculate VaR, some of which are:

  • Parametric Approach (Variance...