Python for Finance - Second Edition

Constructing an efficient frontier with n stocks

When the number of stocks, n, increases, the correlation between each pair of stocks increases dramatically. For n stocks, we have n*(n-1)/2 correlations. For example, if n is 10, we have 45 correlations. Because of this, it is not a good idea to manually input those values. Instead, we generate means, standard deviations, and correlations by drawing random numbers from several uniform distributions. To produce correlated returns, first we generate n uncorrelated stock return time series and then apply Cholesky decomposition as follows:

import numpy as np import scipy as sp import pandas as pd import matplotlib.pyplot as plt from datetime import datetime as dt from scipy.optimize import minimize ...