坚持使用线性优化函数来优化投资组合权重

Stuck using the linear optimisation function to optimise portfolio weights

上下文

我目前正在寻求建立一个优化函数来构建投资组合权重。它类似于 excel 求解器或 google 工作表求解器函数(尽管有缺陷)。尽管它的工作方式与 excel VBA 不同。这是我第一次玩它。以下是脚本:

function PortfolioOptimisation() {
    const ss = SpreadsheetApp.getActiveSpreadsheet();
    var assets = ['AssetOne','AssetTwo','AssetThree','AssetFour','AssetFive',
                  'AssetSix','AssetSeven','AssetEight']; //What I using to optimise variables
    var weights = ss.getRangeByName(assets); 
    // The variables to optimise
    var factors = ['OptimisationExpectedReturn','OptimisationExpectedVol','OptimisationNegativeReturn',
                   'OptimisationPositiveReturns','OptimisationPositiveRisk','OptimisationNegativeRisk',
                   'OptimisationSortinoRatio','OptimisationSharpeRatio']; //Store it in a variable as I do not want to keep typing up the named ranges. 
    var sumWeights = ss.getRangeByName('OptimisationWeightsSum')
    var optimalPortfolios = ss.getRangeByName(factors);


    // Call the optimiser engine
    var engine = LinearOptimizationService.createEngine();
    engine.addVariable(optimalPortfolios[0]);// Add first variable,
    // Add constraints: weights =1, Sum of weights =1, weights = greater than 0, less than or equal to 1.
    var constraint = engine.addConstraints([0.0],[1.0],[weights,sumWeights],[weights]);
    

这就是我试图将其应用于: Spreadsheet

它包含将使用优化函数计算的每个单元格中的公式。

问题

如何执行优化功能以根据电子表格中的 'portfolio section/column' 找到最佳值?我怎样才能改进上面的代码?

例如,在电子表格的第二个 tab/sheet 中,在第一个投资组合名称上,我想通过最大化和最小化 Sortino 比率来优化资产的权重。那么使用优化引擎,可以帮助我实现这一目标的最佳资产权重是多少?我想对投资组合列中列出的其他投资组合做同样的事情。

the documentation 中所述,要找到最佳值,您应该 运行 engine.solve()。这将 return 值,因此您需要将它们存储在一个变量中,然后在任何您想要的地方使用它们。

...
var constraint = engine.addConstraints([0.0],[1.0],[weights,sumWeights],[weights]);

// Get the result of the optimization engine
var solution = engine.solve()

另外请记住,solve() has a default deadline of 30 seconds. If you want to modify the default deadline time simply pass the amount of seconds you want as a paramater like this engine.solve(300). Also, check these methods 可以应用于您的解决方案,例如,确定它是否可行或最佳。

一个python解决方案

def ticker_list():
    tckr_list = ['AVV.L', 'SCT.L', 'ROR.L', 'OCDO.L', 'CCC.L', '3IN.L', 'AVST.L', 'ASC.L', 'SPX.L','ECM.L', 'TRN.L', 'PLTR']
    return tckr_list

def Optimize_MaxR_Vc():
    # after getting a list of your asset returns...
    
    # Number of assets in the portfolio
    tckr_list = ticker_list() # this should be for the number of assets you have. if saved as a
    Assets = tckr_list
    num_assets = len(Assets)

    # Lists of variables for Portfolio creation
    Portfolio_returns = []
    Portfolio_Volatilities = []
    Portfolio_GrossR = []
    Aveva_Returns_weight = []
    Softcat_Returns_weight = []
    Rotork_Returns_weight = []
    Ocado_Returns_weight = []
    Computacenter_Returns_weight = [] 
    TInfrastructure_Returns_weight = []
    Avast_Returns_weight = []
    ASOS_Returns_weight = []
    Spirax_Returns_weight = []
    Electrocomponents_Returns_weight = [] 
    Trainline_Returns_weight = []
    Palantir_Returns_weight = []

    #Optimising for expected returns and standard deviation
    Gross_rtn = Gross_return()

    for x in range (100000):
        weights = np.random.random(num_assets)
        weights /= np.sum(weights)
        Portfolio_returns.append(np.sum(weights * Portfolio_rtns.mean() * 250)) # expected returns
        Portfolio_Volatilities.append(np.sqrt(np.dot(weights.T,np.dot(Portfolio_rtns.cov() * 250, weights)))) # standard deviation 
        Portfolio_GrossR.append(np.sum(weights * Gross_rtn.mean() * 250)) # Gross returns
        Aveva_Returns_weight.append(weights[0])
        Softcat_Returns_weight.append(weights[1])  
        Rotork_Returns_weight.append(weights[2]) 
        Ocado_Returns_weight .append(weights[3]) 
        Computacenter_Returns_weight.append(weights[4]) 
        TInfrastructure_Returns_weight.append(weights[5])
        Avast_Returns_weight.append(weights[6])  
        ASOS_Returns_weight.append(weights[7])
        Spirax_Returns_weight.append(weights[8])
        Electrocomponents_Returns_weight.append(weights[9])
        Trainline_Returns_weight.append(weights[10])
        Palantir_Returns_weight.append(weights[11])

        # Create an array of data for portfolio
    Portfolio_returns = np.array(Portfolio_returns)
    Portfolio_Volatilities = np.array(Portfolio_Volatilities)
    Portfolio_GrossR = np.array(Portfolio_GrossR)
    Aveva_Returns_Weight = np.array(Aveva_Returns_weight)
    Softcat_Returns_Weight = np.array(Softcat_Returns_weight)
    Rotork_Returns_Weight = np.array(Rotork_Returns_weight)
    Ocado_Returns_Weight = np.array(Ocado_Returns_weight)
    Computacenter_Returns_Weight = np.array(Computacenter_Returns_weight)
    TInfrastructure_Returns_Weight = np.array(TInfrastructure_Returns_weight)
    Avast_Returns_Weight = np.array(Avast_Returns_weight)
    ASOS_Returns_Weight = np.array(ASOS_Returns_weight)
    Spirax_Returns_Weight = np.array(Spirax_Returns_weight)
    Electrocomponents_Returns_Weight = np.array(Electrocomponents_Returns_weight)
    Trainline_Returns_Weight = np.array(Trainline_Returns_weight)
    Palantir_Returns_Weight = np.array(Palantir_Returns_weight)


    #Creating a table
    Portfolios = pd.DataFrame({'Return': Portfolio_returns, 
                           'Volatility': Portfolio_Volatilities,
                           'Gross Return': Portfolio_GrossR,
                           'Aveva Weight': Aveva_Returns_weight,
                           'Softcat Weight': Softcat_Returns_weight, 
                           'Rotork Weight': Rotork_Returns_weight,
                            'Ocado Weight': Ocado_Returns_weight,  
                            'Computacenter Weight': Computacenter_Returns_weight,
                            '3Infrastructure Weight': TInfrastructure_Returns_weight,
                            'Avast Weight': Avast_Returns_weight,
                            'ASOS Weight': ASOS_Returns_weight,
                            'Spirax Weight': Spirax_Returns_weight,
                            'Electrocomponents': Electrocomponents_Returns_weight,
                            'Trainline': Trainline_Returns_weight,
                            'Palantir': Palantir_Returns_weight})


        # Custom Portfolios

# With this range, what different types of portfolios can we build? 
    # if volatitlity is within this range, where is volatility when you search for max return?
    Min_return = Portfolios[(Portfolios['Volatility']>=.135) & (Portfolios['Volatility']<=14.358)].min()['Return']
    Return = Portfolios.iloc[np.where(Portfolios['Return']==Min_return)]
    Min_return_1 = Portfolios[(Portfolios['Volatility']>=.200) & (Portfolios['Volatility']<=9.00)].min()['Return']
    Return_2 = Portfolios.iloc[np.where(Portfolios['Return']==Min_return_1)]
    Min_return_2 = Portfolios[(Portfolios['Volatility']>=.300) & (Portfolios['Volatility']<=8.00)].min()['Return']
    Return_3 = Portfolios.iloc[np.where(Portfolios['Return']==Min_return_2)]
    Min_return_3 = Portfolios[(Portfolios['Volatility']>=.400) & (Portfolios['Volatility']<=7.00)].min()['Return']
    Return_4 = Portfolios.iloc[np.where(Portfolios['Return']==Min_return_3)]
    Min_return_4 = Portfolios[(Portfolios['Volatility']>=.500) & (Portfolios['Volatility']<=6.00)].min()['Return']
    Return_5 = Portfolios.iloc[np.where(Portfolios['Return']==Min_return_4)]
    Min_return_5 = Portfolios[(Portfolios['Volatility']>=.600) & (Portfolios['Volatility']<=5.00)].min()['Return']
    Return_6 = Portfolios.iloc[np.where(Portfolios['Return']==Min_return_5)]
    Min_return_6 = Portfolios[(Portfolios['Volatility']>=.700) & (Portfolios['Volatility']<=4.00)].min()['Return']
    Return_7 = Portfolios.iloc[np.where(Portfolios['Return']==Min_return_6)]
    Min_return_7 = Portfolios[(Portfolios['Volatility']>=.800) & (Portfolios['Volatility']<=3.00)].min()['Return']
    Return_8= Portfolios.iloc[np.where(Portfolios['Return']==Min_return_7)]
    Min_return_8 = Portfolios[(Portfolios['Volatility']>=.900) & (Portfolios['Volatility']<=2.00)].min()['Return']
    Return_8= Portfolios.iloc[np.where(Portfolios['Return']==Min_return_8)]
    Min_return_9 = Portfolios[(Portfolios['Volatility']>=.100) & (Portfolios['Volatility']<=1.00)].min()['Return']
    Return_9= Portfolios.iloc[np.where(Portfolios['Return']==Min_return_9)]
    
    Final_MaxOp = pd.concat([Return,Return_2, Return_3, Return_4, Return_5, Return_6,
                        Return_7, Return_8, Return_9])

    return Final_MaxOp

我将它保存为 python 实验室中的一个模块,因此要 运行 它,我需要做的就是:

Portfolio = P.Optimize_MaxR_Vc() # load the results

Portfolio # show the results

P 是我保存它的模块,所以我将它导入为 from Portfolio import P

在提出范围之前,运行:

  # What is the max returns? 
   max(Portfolio_returns)
    
  #What is the min volatility?
   min(Portfolio_Volatilities)

您可以将这段代码的各个部分分成不同的函数,运行它们可以测试不同的范围。

更新

更简单的解决方案:

# Portfolio returns calculated
def portfolio_returns(weights, returns):
    """weights -> returns"""
    
    # take the weights, transpose it and take the matrix multiplication
    return weights.T @ returns

# Volatility
def portfolio_volatility(weights, covmat):
    """Weights -> Covariance"""
    
    # Weights transposes, matrix multiply with covmatrix and matrix multiply this with weights and square root the answer
    return (weights.T @ covmat @ weights)**0.5

# minimum vol for a certain return
from scipy.optimize import minimize
import numpy as np

def minimize_vol (target_return, er, Cov):
    
    # number of assets
    n = er.shape[0]
    # guess weights to achieve goal
    initial_guess = np.repeat(1/n, n)
    # make copies of this boundary for every asset
    boundary = ((0.0, 1.0),)*n
    # Return should be whatever the target is
    return_is_target = {
        'type': 'eq',
        'args': (er,),
        'fun': lambda weights, er: target_return - portfolio_returns(weights, er)
        
    }
    # weights should equal one
    weights_sum_1 = {
        'type':'eq',
        'fun': lambda weights: np.sum(weights) - 1
    }
    # Optimiser
    results = minimize(portfolio_volatility, initial_guess,
                       args=(cov,), method='SLSQP',
                       options={'disp': False},
                       constraints=(return_is_target, weights_sum_1),
                       bounds=boundary)
    return results.x

# Target weights
def optimal_weights(n_points, er, cov):
    """ Get a list of weights for min and max returns"""
    # generate the target return give the min and max returns
    target_rtns = np.linspace(er.min(), er.max(), n_points)
    # for target rtns, loop through the function for what this would be and give me a set of weights
    weights = [minimize_vol(target_return, er, cov) for target_return in target_rtns]
    return weights

# multi asset portfolio for mimimum volatility portfolio
def plot_Portfolio(n_points, er, cov):
    """
    plot Efficient portfolio for n assets
    """
    weights = optimal_weights(n_points, er, cov)
    Returns = [portfolio_returns(w,er) for w in weights]
    Covariance = [portfolio_volatility(w,cov) for w in weights]
    Portfolio_final = pd.DataFrame({"Returns":Returns, "Volatility": Covariance})
    return Portfolio_final.plot.line(x="Volatility", y="Returns");

--> 源自 Edhec 课程