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quantconnect--lean/Algorithm.Framework/Portfolio/UnconstrainedMeanVariancePortfolioOptimizer.py
2019-04-03 21:55:43 -03:00

37 lines
1.9 KiB
Python

# QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
# Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from numpy import dot
from numpy.linalg import inv
### <summary>
### Provides an implementation of a portfolio optimizer with unconstrained mean variance.'''
### </summary>
class UnconstrainedMeanVariancePortfolioOptimizer:
'''Provides an implementation of a portfolio optimizer with unconstrained mean variance.'''
def Optimize(self, historicalReturns, expectedReturns = None, covariance = None):
'''
Perform portfolio optimization for a provided matrix of historical returns and an array of expected returns
args:
historicalReturns: Matrix of annualized historical returns where each column represents a security and each row returns for the given date/time (size: K x N).
expectedReturns: Array of double with the portfolio annualized expected returns (size: K x 1).
covariance: Multi-dimensional array of double with the portfolio covariance of annualized returns (size: K x K).</param>
Returns:
Array of double with the portfolio weights (size: K x 1)
'''
if expectedReturns is None:
expectedReturns = historicalReturns.mean()
if covariance is None:
covariance = historicalReturns.cov()
return expectedReturns.dot(inv(covariance))