def test_idzorek_with_priors():
df = get_data()
S = risk_models.sample_cov(df)
mcaps = get_market_caps()
viewdict = {"GOOG": 0.40, "AAPL": -0.30, "FB": 0.30, "BABA": 0}
bl = BlackLittermanModel(
S,
pi="market",
market_caps=mcaps,
absolute_views=viewdict,
omega="idzorek",
view_confidences=[1, 1, 0.25, 0.25],
)
rets = bl.bl_returns()
assert bl.omega[0, 0] == 0
np.testing.assert_almost_equal(rets["AAPL"], -0.3)
with pytest.raises(ValueError):
bl.portfolio_performance()
bl.bl_weights()
np.testing.assert_allclose(
bl.portfolio_performance(),
(0.943431295405105, 0.5361412623208567, 1.722365653051476),
)
# Check that bl.cov() has been called and used
assert bl.posterior_cov is not None
def test_bl_market_prior():
df = get_data()
S = risk_models.sample_cov(df)
prices = pd.read_csv(resource("spy_prices.csv"),
parse_dates=True,
index_col=0,
squeeze=True)
delta = black_litterman.market_implied_risk_aversion(prices)
mcaps = get_market_caps()
prior = black_litterman.market_implied_prior_returns(mcaps, delta, S)
viewdict = {"GOOG": 0.40, "AAPL": -0.30, "FB": 0.30, "BABA": 0}
bl = BlackLittermanModel(S, pi=prior, absolute_views=viewdict)
rets = bl.bl_returns()
# compare posterior with prior
for v in viewdict:
assert (prior[v] <= rets[v] <= viewdict[v]) or (viewdict[v] <= rets[v]
<= prior[v])
with pytest.raises(ValueError):
bl.portfolio_performance()
bl.bl_weights(delta)
np.testing.assert_allclose(
bl.portfolio_performance(),
(0.2580693114409672, 0.265445955488424, 0.8968654692926723),
)
# Check that bl.cov() has been called and used
assert bl.posterior_cov is not None
def test_black_litterman_market_prior():
df = get_data()
S = risk_models.sample_cov(df)
prices = pd.read_csv(
"tests/spy_prices.csv", parse_dates=True, index_col=0, squeeze=True
)
delta = black_litterman.market_implied_risk_aversion(prices)
mcaps = {
"GOOG": 927e9,
"AAPL": 1.19e12,
"FB": 574e9,
"BABA": 533e9,
"AMZN": 867e9,
"GE": 96e9,
"AMD": 43e9,
"WMT": 339e9,
"BAC": 301e9,
"GM": 51e9,
"T": 61e9,
"UAA": 78e9,
"SHLD": 0,
"XOM": 295e9,
"RRC": 1e9,
"BBY": 22e9,
"MA": 288e9,
"PFE": 212e9,
"JPM": 422e9,
"SBUX": 102e9,
}
prior = black_litterman.market_implied_prior_returns(mcaps, delta, S)
viewdict = {"GOOG": 0.40, "AAPL": -0.30, "FB": 0.30, "BABA": 0}
bl = BlackLittermanModel(S, pi=prior, absolute_views=viewdict)
rets = bl.bl_returns()
# compare posterior with prior
for v in viewdict:
assert (prior[v] <= rets[v] <= viewdict[v]) or (
viewdict[v] <= rets[v] <= prior[v]
)
with pytest.raises(ValueError):
bl.portfolio_performance()
bl.bl_weights(delta)
np.testing.assert_allclose(
bl.portfolio_performance(),
(0.2580693114409672, 0.265445955488424, 0.8968654692926723),
)
# Check that bl.cov() has been called and used
assert bl.posterior_cov is not None
def test_bl_equal_prior():
df = get_data()
S = risk_models.sample_cov(df)
viewdict = {"AAPL": 0.20, "BBY": -0.30, "BAC": 0, "SBUX": -0.2, "T": 0.131321}
bl = BlackLittermanModel(S, absolute_views=viewdict, pi="equal")
np.testing.assert_array_almost_equal(bl.pi, np.ones((20, 1)) * 0.05)
bl.bl_weights()
np.testing.assert_allclose(
bl.portfolio_performance(),
(0.1877432247395778, 0.3246889329226965, 0.5166274785827545),
)
