Quant BuffetRelax, Not Over Thinking

Technical Indicators Predict Cross-Sectional Expected Stock Returns

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Academic paper

Technical Indicators and Cross-Sectional Expected Returns

AuthorsHui Zeng; Ben R. Marshall; Nhut H. Nguyen; Nuttawat Visaltanachoti

Institute
  • NZMassey University
  • ?Massey University - Department of Economics and Finance
  • ?Massey University - School of Economics and Finance
  • NZAuckland University of Technology

Strategy in a nutshell

The investment universe includes all firms listed on NYSE, AMEX, and NASDAQ from the CRSP database. Firms with fewer than 60 monthly return observations are excluded. Fourteen firm-level technical indicators are constructed based on three trend-following strategies: moving average, momentum, and volume-based rules.

Moving Average Rule: Trading signals are generated by comparing short- and long-term moving averages.

Momentum Rule: Signals arise from comparing the current stock price with its level n months ago.

On-Balance Volume Rule: Signals are based on changes in trading volume.

Each month ttt, stock iii’s return is regressed on the 14 technical indicators from month t−1t-1t−1, using a rolling 60-month window to estimate the next month’s return. To mitigate overfitting, the time-series average of the cross-sectional OLS coefficients is calculated using a 60-month smoothing window. At month-end, stocks are sorted into value-weighted deciles based on their estimated returns. The top decile is bought and the bottom decile is sold. The resulting long-short portfolio is value-weighted and rebalanced monthly.

Economic rationale

Trend-following strategies generate buy (sell) signals in response to positive (negative) market trends, reflected by recent price increases (decreases). Technical indicators have been shown to predict stock returns effectively. Zhu and Zhou (2009) theoretically demonstrate how technical analysis enhances asset allocation between risk-free bonds and predictable stocks. Empirical studies, such as Zeng, Marshall, Nguyen, and Visaltanachoti (2021), find that technical indicators have significant predictive power, especially for firms with high limits to arbitrage. Combining multiple trend-following indicators improves the model’s ability to detect stock price trends and explains cross-sectional variations in stock returns.

Backtest performance

Annualised return41.91%
Volatility11.78%
Beta0.006
Sharpe ratio2.73
Sortino ratio-0.157
Win rate51%

Full Python code

from AlgorithmImports import *
import statsmodels.api as sm
# endregion

class TechnicalIndicatorsPredictCrossSectionalExpectedStockReturns(QCAlgorithm):

def Initialize(self):
self.SetStartDate(2000, 1, 1)
self.SetCash(100000)

self.quantile:int = 10
self.month_period:int = 21    
self.regression_period:int = 60
self.period:int = self.month_period * 12               
self.leverage:int = 5
self.long_periods:List[int] = [9 * self.month_period, 12 * self.month_period]
self.short_periods:List[int] = [1* self.month_period, 2 * self.month_period, 3 * self.month_period]

self.last_fine:List[Symbol] = []

self.data:Dict[Symbol, SymbolData] = {}
self.weight:Dict[Symbol, float] = {}

self.symbol:Symbol = self.AddEquity('SPY', Resolution.Daily).Symbol

self.fundamental_count:int = 500
self.fundamental_sorting_key = lambda x: x.DollarVolume

self.selection_flag:bool = False
self.UniverseSettings.Resolution = Resolution.Daily
self.AddUniverse(self.FundamentalSelectionFunction)
self.Settings.MinimumOrderMarginPortfolioPercentage = 0.
self.Schedule.On(self.DateRules.MonthStart(self.symbol), self.TimeRules.BeforeMarketClose(self.symbol, 0), self.Selection)

def OnSecuritiesChanged(self, changes: SecurityChanges) -> None:
for security in changes.AddedSecurities:
    security.SetFeeModel(CustomFeeModel())
    security.SetLeverage(self.leverage)

def FundamentalSelectionFunction(self, fundamental: List[Fundamental]) -> None:
# update stocks data on daily basis
for stock in fundamental:
    symbol:Symbol = stock.Symbol
    
    if symbol in self.data:
        self.data[symbol].update(stock.AdjustedPrice, stock.Volume)

if not self.selection_flag:
    return Universe.Unchanged

selected:List[Fundamental] = [x for x in fundamental if x.HasFundamentalData and x.Market == 'usa' and x.MarketCap != 0 and \
    ((x.SecurityReference.ExchangeId == "NYS") or (x.SecurityReference.ExchangeId == "NAS") or (x.SecurityReference.ExchangeId == "ASE"))]

if len(selected) > self.fundamental_count:
    selected = [x for x in sorted(selected, key=self.fundamental_sorting_key, reverse=True)[:self.fundamental_count]]

pred_returns:Dict[Fundamental, float] = {}

# warm up stock's data
for stock in selected:
    symbol:Symbol = stock.Symbol

    if symbol not in self.data:
        self.data[symbol] = SymbolData(symbol, self.short_periods, self.long_periods, self.period)
        history = self.History(symbol, self.period, Resolution.Daily)
        if history.empty:
            continue
        
        closes = history.loc[symbol].close
        volumes = history.loc[symbol].volume

        for (_, close), (_, volume) in zip(closes.items(), volumes.items()):
            self.data[symbol].update(close, volume)
    
    if self.data[symbol].is_ready():
        symbol_obj = self.data[symbol]

        # make sure data are consecutive
        if symbol not in self.last_fine:
            symbol_obj.clear_regression_data()

        # make sure regression data are ready
        if symbol_obj.is_regression_data_ready(self.regression_period):
            regression_x, regression_y = symbol_obj.get_regression_data(self.regression_period)
            x_transpose:np.array = np.array(regression_x).T

            # skip x series with the same value throughout the whole series since there's not clear decision to make for which zeroed series should be intercept
            x_variable_skip_indices:List[int] = self.GetIndicesOfSameValues(x_transpose=x_transpose)

            # use adjusted x variable for model building and for prediction
            adjusted_x_variable:List = [x for i, x in enumerate(x_transpose) if i not in x_variable_skip_indices]
            regression_x:np.array = np.array(adjusted_x_variable).T
            regression_model = sm.OLS(endog=regression_y, exog=regression_x).fit()
            regression_params:List[float] = list(regression_model.params)

            # update this month regression data
            symbol_obj.update_returns(self.month_period)
            symbol_obj.update_technical_indicators(self.long_periods)

            if symbol_obj.is_smoothing_window_ready(self.regression_period):
                pred_params:List = symbol_obj.get_prediction_params(self.regression_period)
                pred_x:List = symbol_obj.get_prediction_x()

                # predict price based on previous technical indicators
                stock_pred_return:float = self.CalcStockPrediction(pred_params, pred_x)

                pred_returns[stock] = stock_pred_return

            # update smoothing window
            smoothing_window_entry:List[float] = []
            for i, x_series in enumerate(x_transpose):
                if i in x_variable_skip_indices:
                    smoothing_window_entry.append(0)
                else:
                    smoothing_window_entry.append(regression_params.pop(0))

            symbol_obj.update_smoothing_window(smoothing_window_entry)

        else:
            # update this month regression data
            symbol_obj.update_returns(self.month_period)
            symbol_obj.update_technical_indicators(self.long_periods)

# last_fine helps to secure data consecution
self.last_fine = list(map(lambda x: x.Symbol, selected))

# make sure there are enough stock for selection
if len(pred_returns) < self.quantile:
    return Universe.Unchanged

quantile:int = int(len(pred_returns) / self.quantile)
sorted_by_pred_returns:List[Fundamental] = [x[0] for x in sorted(pred_returns.items(), key=lambda item: item[1])]

# buy stocks with the highest expected return
long_part = sorted_by_pred_returns[-quantile:]

# sell stocks with the lowest expected return
short_part = sorted_by_pred_returns[:quantile]

for i, portfolio in enumerate([long_part, short_part]):
    total_long_cap:float = sum([x.MarketCap for x in portfolio])
    for stock in portfolio:
        self.weight[stock.Symbol] = ((-1) ** i) * stock.MarketCap / total_long_cap

return list(self.weight.keys())

def OnData(self, data: Slice) -> None:
# rebalance monthly
if not self.selection_flag:
    return
self.selection_flag = False

# trade execution
portfolio:List[PortfolioTarget] = [PortfolioTarget(symbol, w) for symbol, w in self.weight.items() if symbol in data and data[symbol]]
self.SetHoldings(portfolio, True)

self.weight.clear()

def GetIndicesOfSameValues(self, x_transpose:np.array) -> list:
x_variable_skip_indices:List= []

for i, x_series in enumerate(x_transpose):
    # don't skip intercept
    if i != 0 and all(x_series[0] == x for x in x_series):
        x_variable_skip_indices.append(i)

return x_variable_skip_indices

def CalcStockPrediction(self, pred_params:List, pred_x:List) -> float:
pred_value:float = 0

for param, x_value in zip(pred_params, pred_x):
    pred_value += param * x_value

return pred_value

def Selection(self) -> NormalizedNetProfitMargin():
self.selection_flag = True

class SymbolData():
def __init__(self, symbol:Symbol, short_periods:List, long_periods:List, period:float) -> None:
self.short_SMA:List = []
self.long_SMA:List = []

self.long_volumes:List = []
self.short_volumes:List = []

self.technical_indicators:List = []
self.returns:List = []

self.smoothing_window:List = []

self.prices:RollingWindow = RollingWindow[float](period)

for period in short_periods:
    self.short_SMA.append(RollingWindow[float](period))
    self.short_volumes.append(RollingWindow[float](period))

for period in long_periods:
    self.long_SMA.append(RollingWindow[float](period))
    self.long_volumes.append(RollingWindow[float](period))

def update(self, stock_price:float, stock_volume:float) -> None:
for short_SMA_roll_win, short_volume in zip(self.short_SMA, self.short_volumes):
    short_SMA_roll_win.Add(stock_price)
    short_volume.Add(stock_volume)

for long_SMA_roll_win, long_volume in zip(self.long_SMA, self.long_volumes):
    long_SMA_roll_win.Add(stock_price)
    long_volume.Add(stock_volume)

self.prices.Add(stock_price)

def is_ready(self) -> bool:
for short_SMA_roll_win, short_volume in zip(self.short_SMA, self.short_volumes):
    if not short_SMA_roll_win.IsReady or not short_volume.IsReady:
        return False

for long_SMA_roll_win, long_volume in zip(self.long_SMA, self.long_volumes):
    if not long_SMA_roll_win.IsReady or not long_volume.IsReady:
        return False

return self.prices.IsReady

def is_regression_data_ready(self, regression_period:int) -> bool:
return len(self.technical_indicators) >= regression_period and len(self.returns) >= regression_period

def is_smoothing_window_ready(self, regression_period:int) -> bool:
return len(self.smoothing_window) >= regression_period

def clear_regression_data(self):
self.technical_indicators.clear()
self.smoothing_window.clear()
self.returns.clear()

def update_returns(self, period:int):
# make sure between regression x and y is right shift
if len(self.technical_indicators) > 0:
    prices:List = [x for x in self.prices][:period]
    return_value:float = (prices[0] - prices[-1]) / prices[-1]

    self.returns.append(return_value)

def update_technical_indicators(self, periods:List) -> list:
technical_indicators_values:List = []

# MA and OBV technical indicators
for long_SMA_roll_win, long_volume in zip(self.long_SMA, self.long_volumes):
    mean_long_volume:float = np.mean([x for x in long_volume])
    long_SMA_value:float = self.calc_simple_moving_average([x for x in long_SMA_roll_win])

    for short_SMA_roll_win, short_volume in zip(self.short_SMA, self.short_volumes):
        mean_short_volume:float = np.mean([x for x in short_volume])
        short_SMA_value:float = self.calc_simple_moving_average([x for x in short_SMA_roll_win])

        if long_SMA_value > short_SMA_value:
            technical_indicators_values.append(0)
        else:
            technical_indicators_values.append(1)

        if mean_long_volume > mean_short_volume:
            technical_indicators_values.append(0)
        else:
            technical_indicators_values.append(1)

prices:List = [x for x in self.prices]
curr_price:float = prices[0]

# MOM technical indicators
for period in periods:
    if curr_price >= prices[period - 1]:
        technical_indicators_values.append(1)
    else:
        technical_indicators_values.append(0)

self.technical_indicators.append(technical_indicators_values)

def update_smoothing_window(self, smoothing_window_entry:List):
self.smoothing_window.append(smoothing_window_entry)

def calc_simple_moving_average(self, prices:List) -> float:
return sum(prices) / len(prices)

def get_regression_data(self, regression_period:int) -> list:
x = self.technical_indicators[-regression_period:]
# add constant
x = [[1] + tech_indi for tech_indi in x]
y = self.returns[-regression_period:]

return x, y

def get_prediction_params(self, regression_period:int) -> list:
window_transpose:np.array = np.array(self.smoothing_window[-regression_period:]).T
params:List = [np.mean(params_list) for params_list in window_transpose]

return params

def get_prediction_x(self) -> list:
last_indicators:List = self.technical_indicators[-1]
return [1] + last_indicators

# Custom fee model
class CustomFeeModel(FeeModel):
def GetOrderFee(self, parameters):
fee = parameters.Security.Price * parameters.Order.AbsoluteQuantity * 0.00005
return OrderFee(CashAmount(fee, "USD"))