def optimization(
self, model="Classic", rm="MV", obj="Sharpe", rf=0, l=2, hist=True
):
r"""
This method that calculates the optimum portfolio according to the
optimization model selected by the user. The general problem that
solves is:
.. math::
\begin{align}
&\underset{x}{\text{optimize}} & & F(w)\\
&\text{s. t.} & & Aw \geq B\\
& & & \phi_{i}(w) \leq c_{i}\\
\end{align}
Where:
:math:`F(w)` is the objective function.
:math:`Aw \geq B` is a set of linear constraints.
:math:`\phi_{i}(w) \leq c_{i}` are constraints on maximum values of
several risk measures.
Parameters
----------
model : str can be 'Classic', 'BL' or 'FM'
The model used for optimize the portfolio.
The default is 'Classic'. Posible values are:
- 'Classic': use estimates of expected return vector and covariance matrix that depends on historical data.
- 'BL': use estimates of expected return vector and covariance matrix based on the Black Litterman model.
- 'FM': use estimates of expected return vector and covariance matrix based on a Risk Factor model specified by the user.
rm : str, optional
The risk measure used to optimze the portfolio.
The default is 'MV'. Posible values are:
- 'MV': Standard Deviation.
- 'MAD': Mean Absolute Deviation.
- 'MSV': Semi Standard Deviation.
- 'FLPM': First Lower Partial Moment (Omega Ratio).
- 'SLPM': Second Lower Partial Moment (Sortino Ratio).
- 'CVaR': Conditional Value at Risk.
- 'WR': Worst Realization (Minimax)
- 'MDD': Maximum Drawdown of uncompounded returns (Calmar Ratio).
- 'ADD': Average Drawdown of uncompounded returns.
- 'CDaR': Conditional Drawdown at Risk of uncompounded returns.
obj : str can be {'MinRisk', 'Utility', 'Sharpe' or 'MaxRet'.
Objective function of the optimization model.
The default is 'Sharpe'. Posible values are:
- 'MinRisk': Minimize the selected risk measure.
- 'Utility': Maximize the Utility function :math:`mu w - l \phi_{i}(w)`.
- 'Sharpe': Maximize the risk adjusted return ratio based on the selected risk measure.
- 'MaxRet': Maximize the expected return of the portfolio.
rf : float, optional
Risk free rate, must be in the same period of assets returns.
The default is 0.
l : scalar, optional
Risk aversion factor of the 'Utility' objective function.
The default is 2.
hist : bool, optional
Indicate if uses historical or factor estimation of returns to
calculate risk measures that depends on scenarios (All except
'MV' risk measure). The default is True.
Returns
-------
w : DataFrame
The weights of optimum portfolio.
"""
# General model Variables
mu = None
sigma = None
returns = None
if model == "Classic":
mu = np.matrix(self.mu)
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
elif model == "FM":
mu = np.matrix(self.mu_fm)
if hist == False:
sigma = np.matrix(self.cov_fm)
returns = np.matrix(self.returns_fm)
nav = np.matrix(self.nav_fm)
elif hist == True:
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
elif model == "BL":
mu = np.matrix(self.mu_bl)
if hist == False:
sigma = np.matrix(self.cov_bl)
elif hist == True:
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
elif model == "BL_FM":
mu = np.matrix(self.mu_bl_fm)
if hist == False:
sigma = np.matrix(self.cov_bl_fm)
returns = np.matrix(self.returns_fm)
nav = np.matrix(self.nav_fm)
elif hist == True:
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
# General Model Variables
returns = np.matrix(returns)
w = cv.Variable((mu.shape[1], 1))
k = cv.Variable((1, 1))
rf0 = cv.Parameter(nonneg=True)
rf0.value = rf
n = cv.Parameter(nonneg=True)
n.value = returns.shape[0]
ret = mu * w
# MV Model Variables
risk1 = cv.quad_form(w, sigma)
returns_1 = af.cov_returns(sigma) * 1000
n1 = cv.Parameter(nonneg=True)
n1.value = returns_1.shape[0]
risk1_1 = cv.norm(returns_1 * w, "fro") / cv.sqrt(n1 - 1)
# MAD Model Variables
madmodel = False
Y = cv.Variable((returns.shape[0], 1))
u = np.matrix(np.ones((returns.shape[0], 1)) * mu)
a = returns - u
risk2 = cv.sum(Y) / n
# madconstraints=[a*w >= -Y, a*w <= Y, Y >= 0]
madconstraints = [a * w <= Y, Y >= 0]
# Semi Variance Model Variables
risk3 = cv.norm(Y, "fro") / cv.sqrt(n - 1)
# CVaR Model Variables
alpha1 = self.alpha
VaR = cv.Variable(1)
alpha = cv.Parameter(nonneg=True)
alpha.value = alpha1
X = returns * w
Z = cv.Variable((returns.shape[0], 1))
risk4 = VaR + 1 / (alpha * n) * cv.sum(Z)
cvarconstraints = [Z >= 0, Z >= -X - VaR]
# Worst Realization (Minimax) Model Variables
M = cv.Variable(1)
risk5 = M
wrconstraints = [-X <= M]
# Lower Partial Moment Variables
lpmmodel = False
lpm = cv.Variable((returns.shape[0], 1))
lpmconstraints = [lpm >= 0]
if obj == "Sharpe":
lpmconstraints += [lpm >= rf0 * k - X]
else:
lpmconstraints += [lpm >= rf0 - X]
# First Lower Partial Moment (Omega) Model Variables
risk6 = cv.sum(lpm) / n
# Second Lower Partial Moment (Sortino) Model Variables
risk7 = cv.norm(lpm, "fro") / cv.sqrt(n - 1)
# Drawdown Model Variables
drawdown = False
if obj == "Sharpe":
X1 = k + nav * w
else:
X1 = 1 + nav * w
U = cv.Variable((nav.shape[0] + 1, 1))
ddconstraints = [U[1:] >= X1, U[1:] >= U[:-1]]
if obj == "Sharpe":
ddconstraints += [U[1:] >= k, U[0] == k]
else:
ddconstraints += [U[1:] >= 1, U[0] == 1]
# Maximum Drawdown Model Variables
MDD = cv.Variable(1)
risk8 = MDD
mddconstraints = [MDD >= U[1:] - X1]
# Average Drawdown Model Variables
risk9 = 1 / n * cv.sum(U[1:] - X1)
# Conditional Drawdown Model Variables
CDaR = cv.Variable(1)
Zd = cv.Variable((nav.shape[0], 1))
risk10 = CDaR + 1 / (alpha * n) * cv.sum(Zd)
cdarconstraints = [Zd >= U[1:] - X1 - CDaR, Zd >= 0]
# Tracking Error Model Variables
c = self.benchweights
if self.kindbench == True:
bench = np.matrix(returns) * c
else:
bench = self.benchindex
if obj == "Sharpe":
TE = cv.norm(returns * w - bench * k, "fro") / cv.sqrt(n - 1)
else:
TE = cv.norm(returns * w - bench, "fro") / cv.sqrt(n - 1)
# Problem aditional linear constraints
if obj == "Sharpe":
constraints = [
cv.sum(w) == self.upperlng * k,
k >= 0,
mu * w - rf0 * k == 1,
]
if self.sht == False:
constraints += [w <= self.upperlng * k, w * 1000 >= 0]
elif self.sht == True:
constraints += [
w <= self.upperlng * k,
w >= -self.uppersht * k,
cv.sum(cv.neg(w)) <= self.uppersht * k,
]
else:
constraints = [cv.sum(w) == self.upperlng]
if self.sht == False:
constraints += [w <= self.upperlng, w * 1000 >= 0]
elif self.sht == True:
constraints += [
w <= self.upperlng,
w >= -self.uppersht,
cv.sum(cv.neg(w)) <= self.uppersht,
]
if self.ainequality is not None and self.binequality is not None:
A = np.matrix(self.ainequality)
B = np.matrix(self.binequality)
if obj == "Sharpe":
constraints += [A * w - B * k >= 0]
else:
constraints += [A * w - B >= 0]
# Turnover Constraints
if obj == "Sharpe":
if self.allowTO == True:
constraints += [cv.abs(w - c * k) * 1000 <= self.turnover * k * 1000]
else:
if self.allowTO == True:
constraints += [cv.abs(w - c) * 1000 <= self.turnover * 1000]
# Tracking error Constraints
if obj == "Sharpe":
if self.allowTE == True:
constraints += [TE <= self.TE * k]
else:
if self.allowTE == True:
constraints += [TE <= self.TE]
# Problem risk Constraints
if self.upperdev is not None:
if obj == "Sharpe":
constraints += [risk1_1 <= self.upperdev * k]
else:
constraints += [risk1 <= self.upperdev ** 2]
if self.uppermad is not None:
if obj == "Sharpe":
constraints += [risk2 <= self.uppermad * k / 2]
else:
constraints += [risk2 <= self.uppermad / 2]
madmodel = True
if self.uppersdev is not None:
if obj == "Sharpe":
constraints += [risk3 <= self.uppersdev * k]
else:
constraints += [risk3 <= self.uppersdev]
madmodel = True
if self.upperCVaR is not None:
if obj == "Sharpe":
constraints += [risk4 <= self.upperCVaR * k]
else:
constraints += [risk4 <= self.upperCVaR]
constraints += cvarconstraints
if self.upperwr is not None:
if obj == "Sharpe":
constraints += [-X <= self.upperwr * k]
else:
constraints += [-X <= self.upperwr]
constraints += wrconstraints
if self.upperflpm is not None:
if obj == "Sharpe":
constraints += [risk6 <= self.upperflpm * k]
else:
constraints += [risk6 <= self.upperflpm]
lpmmodel = True
if self.upperslpm is not None:
if obj == "Sharpe":
constraints += [risk7 <= self.upperslpm * k]
else:
constraints += [risk7 <= self.upperslpm]
lpmmodel = True
if self.uppermdd is not None:
if obj == "Sharpe":
constraints += [U[1:] - X1 <= self.uppermdd * k]
else:
constraints += [U[1:] - X1 <= self.uppermdd]
constraints += mddconstraints
drawdown = True
if self.upperadd is not None:
if obj == "Sharpe":
constraints += [risk9 <= self.upperadd * k]
else:
constraints += [risk9 <= self.upperadd]
drawdown = True
if self.upperCDaR is not None:
if obj == "Sharpe":
constraints += [risk10 <= self.upperCDaR * k]
else:
constraints += [risk10 <= self.upperCDaR]
constraints += cdarconstraints
drawdown = True
# Defining risk function
if rm == "MV":
if model != "Classic":
risk = risk1_1
elif model == "Classic":
risk = risk1
elif rm == "MAD":
risk = risk2
madmodel = True
elif rm == "MSV":
risk = risk3
madmodel = True
elif rm == "CVaR":
risk = risk4
if self.upperCVaR is None:
constraints += cvarconstraints
elif rm == "WR":
risk = risk5
if self.upperwr is None:
constraints += wrconstraints
elif rm == "FLPM":
risk = risk6
lpmmodel = True
elif rm == "SLPM":
risk = risk7
lpmmodel = True
elif rm == "MDD":
risk = risk8
drawdown = True
if self.uppermdd is None:
constraints += mddconstraints
elif rm == "ADD":
risk = risk9
drawdown = True
elif rm == "CDaR":
risk = risk10
drawdown = True
if self.upperCDaR is None:
constraints += cdarconstraints
if madmodel == True:
constraints += madconstraints
if lpmmodel == True:
constraints += lpmconstraints
if drawdown == True:
constraints += ddconstraints
# Frontier Variables
portafolio = {}
for i in self.assetslist:
portafolio.update({i: []})
# Optimization Process
# Defining solvers
solvers = [cv.ECOS, cv.SCS, cv.OSQP, cv.CVXOPT, cv.GLPK]
# Defining objective function
if obj == "Sharpe":
if rm != "Classic":
objective = cv.Minimize(risk)
elif rm == "Classic":
objective = cv.Minimize(risk * 1000)
elif obj == "MinRisk":
objective = cv.Minimize(risk)
elif obj == "Utility":
objective = cv.Maximize(ret - l * risk)
elif obj == "MaxRet":
objective = cv.Maximize(ret)
try:
prob = cv.Problem(objective, constraints)
for solver in solvers:
try:
prob.solve(
solver=solver, parallel=True, max_iters=2000, abstol=1e-10
)
except:
pass
if w.value is not None:
break
if obj == "Sharpe":
weights = np.matrix(w.value / k.value).T
else:
weights = np.matrix(w.value).T
if self.sht == False:
weights = np.abs(weights) / np.sum(np.abs(weights))
for j in self.assetslist:
portafolio[j].append(weights[0, self.assetslist.index(j)])
except:
pass
optimum = pd.DataFrame(portafolio, index=["weights"], dtype=np.float64).T
return optimum
def rp_optimization(self,
model="Classic",
rm="MV",
rf=0,
b=None,
hist=True):
r"""
This method that calculates the risk parity portfolio according to the
optimization model selected by the user. The general problem that
solves is:
.. math::
\begin{align}
&\underset{w}{\min} & & R(w)\\
&\text{s.t.} & & b \log(w) \geq c\\
& & & w \geq 0 \\
\end{align}
Where:
:math:`R(w)` is the risk measure.
:math:`b` is a vector of risk constraints.
Parameters
----------
model : str can be 'Classic' or 'FM'
The model used for optimize the portfolio.
The default is 'Classic'. Posible values are:
- 'Classic': use estimates of expected return vector and covariance matrix that depends on historical data.
- 'FM': use estimates of expected return vector and covariance matrix based on a Risk Factor model specified by the user.
rm : str, optional
The risk measure used to optimze the portfolio.
The default is 'MV'. Posible values are:
- 'MV': Standard Deviation.
- 'MAD': Mean Absolute Deviation.
- 'MSV': Semi Standard Deviation.
- 'FLPM': First Lower Partial Moment (Omega Ratio).
- 'SLPM': Second Lower Partial Moment (Sortino Ratio).
- 'CVaR': Conditional Value at Risk.
- 'CDaR': Conditional Drawdown at Risk of uncompounded returns.
rf : float, optional
Risk free rate, must be in the same period of assets returns.
Used for 'FLPM' and 'SLPM'.
The default is 0.
b : float, optional
The vector of risk constraints per asset.
The default is 1/n (number of assets).
hist : bool, optional
Indicate if uses historical or factor estimation of returns to
calculate risk measures that depends on scenarios (All except
'MV' risk measure). The default is True.
Returns
-------
w : DataFrame
The weights of optimum portfolio.
"""
# General model Variables
mu = None
sigma = None
returns = None
if model == "Classic":
mu = np.array(self.mu, ndmin=2)
sigma = np.array(self.cov, ndmin=2)
returns = np.array(self.returns, ndmin=2)
nav = np.array(self.nav, ndmin=2)
elif model == "FM":
mu = np.array(self.mu_fm, ndmin=2)
if hist == False:
sigma = np.array(self.cov_fm, ndmin=2)
returns = np.array(self.returns_fm, ndmin=2)
nav = np.array(self.nav_fm, ndmin=2)
elif hist == True:
sigma = np.array(self.cov, ndmin=2)
returns = np.array(self.returns, ndmin=2)
nav = np.array(self.nav, ndmin=2)
# General Model Variables
if b is None:
b = np.ones((1, mu.shape[1]))
b = b / mu.shape[1]
returns = np.array(returns, ndmin=2)
w = cv.Variable((mu.shape[1], 1))
rf0 = rf
n = returns.shape[0]
# MV Model Variables
risk1 = cv.quad_form(w, sigma)
returns_1 = af.cov_returns(sigma) * 1000
n1 = returns_1.shape[0]
risk1_1 = cv.norm(returns_1 @ w, "fro") / cv.sqrt(n1 - 1)
# MAD Model Variables
Y = cv.Variable((returns.shape[0], 1))
u = np.ones((returns.shape[0], 1)) * mu
a = returns - u
risk2 = cv.sum(Y) / n
# madconstraints=[a*w >= -Y, a*w <= Y, Y >= 0]
madconstraints = [a @ w <= Y, Y >= 0]
# Semi Variance Model Variables
risk3 = cv.norm(Y, "fro") / cv.sqrt(n - 1)
# CVaR Model Variables
alpha1 = self.alpha
VaR = cv.Variable((1, 1))
alpha = alpha1
X = returns @ w
Z = cv.Variable((returns.shape[0], 1))
risk4 = VaR + 1 / (alpha * n) * cv.sum(Z)
cvarconstraints = [Z >= 0, Z >= -X - VaR]
# Lower Partial Moment Variables
lpm = cv.Variable((returns.shape[0], 1))
lpmconstraints = [lpm >= 0, lpm >= rf0 - X]
# First Lower Partial Moment (Omega) Model Variables
risk6 = cv.sum(lpm) / n
# Second Lower Partial Moment (Sortino) Model Variables
risk7 = cv.norm(lpm, "fro") / cv.sqrt(n - 1)
# Drawdown Model Variables
X1 = 1 + nav @ w
U = cv.Variable((nav.shape[0] + 1, 1))
ddconstraints = [
U[1:] * 1000 >= X1 * 1000,
U[1:] * 1000 >= U[:-1] * 1000,
U[1:] * 1000 >= 1 * 1000,
U[0] * 1000 == 1 * 1000,
]
# Conditional Drawdown Model Variables
CDaR = cv.Variable((1, 1))
Zd = cv.Variable((nav.shape[0], 1))
risk10 = CDaR + 1 / (alpha * n) * cv.sum(Zd)
cdarconstraints = [
Zd * 1000 >= U[1:] * 1000 - X1 * 1000 - CDaR * 1000,
Zd * 1000 >= 0,
]
# Defining risk function
constraints = []
if rm == "MV":
if model != "Classic":
risk = risk1_1
elif model == "Classic":
risk = risk1
elif rm == "MAD":
risk = risk2
constraints += madconstraints
elif rm == "MSV":
risk = risk3
constraints += madconstraints
elif rm == "CVaR":
risk = risk4
constraints += cvarconstraints
elif rm == "FLPM":
risk = risk6
constraints += lpmconstraints
elif rm == "SLPM":
risk = risk7
constraints += lpmconstraints
elif rm == "CDaR":
risk = risk10
constraints += ddconstraints
constraints += cdarconstraints
# Frontier Variables
portafolio = {}
for i in self.assetslist:
portafolio.update({i: []})
# Optimization Process
# Defining solvers
solvers = [cv.ECOS, cv.SCS, cv.OSQP, cv.CVXOPT]
sol_params = {
cv.ECOS: {
"max_iters": 2000,
"abstol": 1e-10
},
cv.SCS: {
"max_iters": 2500,
"eps": 1e-10
},
cv.OSQP: {
"max_iter": 10000,
"eps_abs": 1e-10
},
cv.CVXOPT: {
"max_iters": 2000,
"abstol": 1e-10
},
}
# Defining objective function
objective = cv.Minimize(risk * 1000)
constraints += [b @ cv.log(w) * 1000 >= 1 * 1000, w * 1000 >= 0]
try:
prob = cv.Problem(objective, constraints)
for solver in solvers:
try:
prob.solve(solver=solver, **sol_params[solver])
except:
pass
if w.value is not None:
break
weights = np.array(w.value, ndmin=2).T
weights = np.abs(weights) / np.sum(np.abs(weights))
for j in self.assetslist:
portafolio[j].append(weights[0, self.assetslist.index(j)])
except:
pass
rp_optimum = pd.DataFrame(portafolio,
index=["weights"],
dtype=np.float64).T
return rp_optimum
