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Fundamental Algo inspired by Benjamin Graham


I'm trying out an algorithm that picks securities that have fulfilled a few "value" criteria (selected somewhat arbitrarily for now, but inspired by for several times in the past year and then holds on these stocks for as long as they still fulfill these criteria in the past year.

However, there are a few problems with the algorithm:

  1. The algo stops trading mid-2011 because a sell order can't be fulfilled anymore, permanently activating the leverage protection (I prefer to keep the portfolio's cash value nonnegative). Is there a way around this?
  2. Any ideas why num_positions is sometimes non-integer? Is it averaged over all trading days of a particular week?


Clone Algorithm
Backtest from to with initial capital
Total Returns
Max Drawdown
Benchmark Returns
Returns 1 Month 3 Month 6 Month 12 Month
Alpha 1 Month 3 Month 6 Month 12 Month
Beta 1 Month 3 Month 6 Month 12 Month
Sharpe 1 Month 3 Month 6 Month 12 Month
Sortino 1 Month 3 Month 6 Month 12 Month
Volatility 1 Month 3 Month 6 Month 12 Month
Max Drawdown 1 Month 3 Month 6 Month 12 Month
import math
import pandas as pd
import numpy as np


def initialize(context):
    context.num_stocks = 100
    context.needs_rebalance = False
    context.running_day = 0
    context.rebalance_frequency = 20
    context.stocks_per_date = {}
    context.min_holding_period = 365
    context.min_signal_count = 6
    # Sector mappings
    context.sector_mappings = {
       101.0: "Basic Materials",
       102.0: "Consumer Cyclical",
       103.0: "Financial Services",
       104.0: "Real Estate",
       205.0: "Consumer Defensive",
       206.0: "Healthcare",
       207.0: "Utilites",
       308.0: "Communication Services",
       309.0: "Energy",
       310.0: "Industrials",
       311.0: "Technology"
    # Rebalance monthly on the first day of the month at market open
    #                  date_rule=date_rules.month_start(),
    #                  time_rule=time_rules.market_open())

def filter_stocks(context, num_stocks):
    fundamental_df = get_fundamentals(  
    # put your query in here by typing "fundamentals."  
    .filter(fundamentals.valuation.market_cap >= 5e9)  
    .filter(fundamentals.valuation.shares_outstanding != None)  
    .filter(fundamentals.operation_ratios.quick_ratio >= 1.0)  
    .filter(fundamentals.valuation_ratios.pe_ratio > 3.0)  
    .filter(fundamentals.valuation_ratios.pe_ratio < 12.0)  
    .filter(fundamentals.valuation_ratios.pb_ratio < 2.0)
#        .filter(fundamentals.valuation.market_cap                  > 80e6   )  
#        .filter(fundamentals.valuation_ratios.pe_ratio             < 11     )  
#        .filter(fundamentals.valuation_ratios.pe_ratio             > 3      )  
#        .filter(fundamentals.operation_ratios.roa                  > 0.1    )  
#        .filter(fundamentals.balance_sheet.current_debt            < 80e6   )  
#        .filter(fundamentals.valuation_ratios.book_value_per_share > 8      ) 
    #        .filter(fundamentals.valuation_ratios.peg_ratio < 1.5)  
    #print fundamental_df
    current_date = get_datetime()
    stocks = []
    for stock in fundamental_df:
        #sector = fundamental_df[stock]['morningstar_sector_code']
        #pe = fundamental_df[stock]['pe_ratio']
        #peg = fundamental_df[stock]['peg_ratio']
        #pb = fundamental_df[stock]['pb_ratio']
        #bvps = fundamental_df[stock]['book_value_per_share']
        #eps = fundamental_df[stock]['diluted_eps']
        if not stock in context.stocks_per_date:
            context.stocks_per_date[stock] = []
        #print 'stock=%s, sector=%s, pe=%s, peg=%s, pb=%s, bvps=%s, eps=%s' % (stock, sector, pe, peg, pb, bvps, eps)
#         if eps != None and bvps != None:
#             if fundamental_df[stock]['morningstar_sector_code'] == 103:
#                 graham_number = math.sqrt(15 * eps * bvps)
#             else:
#                 graham_number= math.sqrt(22.5 * eps * bvps)
        #graham_margin_of_safety = price / graham_number
    context.fundamental_df = fundamental_df
    for stock in context.stocks_per_date:
        if len(context.stocks_per_date[stock]) >= context.min_signal_count:
            current_signals = 0
            for signal_date in context.stocks_per_date[stock]:
                if (current_date - signal_date).days <= context.min_holding_period:
                    current_signals += 1
            if current_signals >= context.min_signal_count:
    return stocks
def rebalance(context, data):
    # Exit all positions before starting new ones
    for stock in context.portfolio.positions:
        if stock not in context.stocks and not get_open_orders(stock):
            order_target_value(stock, 0)

    # Create weights for each stock
    weight = create_weights(context, context.stocks)

    # Rebalance all stocks to target weights
    stock_symbols = []
    for stock in context.stocks:
        stock_symbols.append(stock.symbol)'weight=%f, symbols=%s' % (weight, stock_symbols))
    for stock in context.stocks:
            if not get_open_orders(stock):
                order_target_percent(stock, weight)
#            print "Unexpected error:", sys.exc_info()[0]

    # track how many positions we're holding
    record(num_positions = len(context.stocks))
    record(cash =

def before_trading_start(context):
    context.running_day += 1
    if context.running_day % context.rebalance_frequency != 1:
    context.stocks = filter_stocks(context, context.num_stocks)
    context.needs_rebalance = True

def create_weights(context, stocks):
        Takes in a list of securities and weights them all equally 
    if len(stocks) == 0:
        return 0 
        weight = 1.0/len(stocks)
        return weight
def handle_data(context, data):
      Code logic to run during the trading day.
      handle_data() gets called every bar.
    orders = has_orders(context, data)
    if orders:
        log.warn('has open orders')
    if not orders and context.needs_rebalance:
        rebalance(context, data)
        context.needs_rebalance = False

def has_orders(context, data):
    # Return true if there are pending orders.
    has_orders = False
    for sec in data:
        orders = get_open_orders(sec)
        if orders:
            for oo in orders:                  
                message = 'Open order for {amount} shares in {stock}'  
                message = message.format(amount=oo.amount, stock=sec)  

            has_orders = True
    return has_orders
There was a runtime error.
1 response

Nice algorithm Daniel. It looks like you are trying to order the stock TAP_A which has a really low volume, so it can't be traded. That's weird, because it has pretty a high market cap. There are a few ways to fix this — I would just try to filter out stocks with a low volume using data[stock].volume to get their volume. You could compare the volume to how many shares you are trying to trade to make sure the volume is greater than that amount.

For your second question, are you talking about the custom data plot? Yeah, the non-integers come up because there are so many data points that some have to be averaged together, like you said. There are only so many pixels!


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