Beispiel #1
0
    def test_volume_share_slippage(self):

        slippage_model = VolumeShareSlippage()

        open_orders = [
            Order(dt=datetime.datetime(2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                  amount=100,
                  filled=0,
                  asset=self.ASSET133)
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[0], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 1)
        _, txn = orders_txns[0]

        expected_txn = {
            'price': float(3.0001875),
            'dt': datetime.datetime(2006, 1, 5, 14, 31, tzinfo=pytz.utc),
            'amount': int(5),
            'asset': self.ASSET133,
            'commission': None,
            'type': DATASOURCE_TYPE.TRANSACTION,
            'order_id': open_orders[0].id
        }

        self.assertIsNotNone(txn)

        # TODO: Make expected_txn an Transaction object and ensure there
        # is a __eq__ for that class.
        self.assertEquals(expected_txn, txn.__dict__)

        open_orders = [
            Order(dt=datetime.datetime(2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                  amount=100,
                  filled=0,
                  asset=self.ASSET133)
        ]

        # Set bar_data to be a minute ahead of last trade.
        # Volume share slippage should not execute when there is no trade.
        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[1], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)
Beispiel #2
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    def test_volume_limit(self, name, first_order_amount, second_order_amount,
                          first_order_fill_amount, second_order_fill_amount):

        slippage_model = FixedBasisPointsSlippage(basis_points=5,
                                                  volume_limit=0.1)

        open_orders = [
            Order(dt=datetime.datetime(2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                  amount=order_amount,
                  filled=0,
                  asset=self.ASSET133)
            for order_amount in [first_order_amount, second_order_amount]
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.first_minute, )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 2)

        _, first_txn = orders_txns[0]
        _, second_txn = orders_txns[1]
        self.assertEquals(first_txn['amount'], first_order_fill_amount)
        self.assertEquals(second_txn['amount'], second_order_fill_amount)
Beispiel #3
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    def test_calculate_impact_without_history(self):
        model = VolatilityVolumeShare(volume_limit=1)
        late_start_asset = self.asset_finder.retrieve_asset(1000)
        early_start_asset = self.asset_finder.retrieve_asset(1001)

        cases = [
            # History will look for data before the start date.
            (pd.Timestamp('2006-01-05 11:35AM', tz='UTC'), early_start_asset),
            # Start day of the futures contract; no history yet.
            (pd.Timestamp('2006-02-10 11:35AM', tz='UTC'), late_start_asset),
            # Only a week's worth of history data.
            (pd.Timestamp('2006-02-17 11:35AM', tz='UTC'), late_start_asset),
        ]

        for minute, asset in cases:
            data = self.create_bardata(simulation_dt_func=lambda: minute)

            order = Order(dt=data.current_dt, asset=asset, amount=10)
            price, amount = model.process_order(data, order)

            avg_price = (data.current(asset, 'high') +
                         data.current(asset, 'low')) / 2
            expected_price = \
                avg_price * (1 + model.NO_DATA_VOLATILITY_SLIPPAGE_IMPACT)

            self.assertAlmostEqual(price, expected_price, delta=0.001)
            self.assertEqual(amount, 10)
Beispiel #4
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    def generate_order_and_txns(self, sid, order_amount, fill_amounts):
        asset1 = self.asset_finder.retrieve_asset(sid)

        # one order
        order = Order(dt=None, asset=asset1, amount=order_amount)

        # three fills
        txn1 = Transaction(asset=asset1,
                           amount=fill_amounts[0],
                           dt=None,
                           price=100,
                           order_id=order.id)

        txn2 = Transaction(asset=asset1,
                           amount=fill_amounts[1],
                           dt=None,
                           price=101,
                           order_id=order.id)

        txn3 = Transaction(asset=asset1,
                           amount=fill_amounts[2],
                           dt=None,
                           price=102,
                           order_id=order.id)

        return order, [txn1, txn2, txn3]
Beispiel #5
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    def test_orders_stop(self, name, order_data, event_data, expected):
        data = order_data
        data['asset'] = self.ASSET133
        order = Order(**data)

        if expected['transaction']:
            expected['transaction']['asset'] = self.ASSET133
        event_data['asset'] = self.ASSET133

        assets = ((133,
                   pd.DataFrame(
                       {
                           'open': [event_data['open']],
                           'high': [event_data['high']],
                           'low': [event_data['low']],
                           'close': [event_data['close']],
                           'volume': [event_data['volume']],
                       },
                       index=[pd.Timestamp('2006-01-05 14:31', tz='UTC')],
                   )), )
        days = pd.date_range(start=normalize_date(self.minutes[0]),
                             end=normalize_date(self.minutes[-1]))
        with tmp_bcolz_equity_minute_bar_reader(self.trading_calendar, days,
                                                assets) as reader:
            data_portal = DataPortal(
                self.env.asset_finder,
                self.trading_calendar,
                first_trading_day=reader.first_trading_day,
                equity_minute_reader=reader,
            )

            slippage_model = VolumeShareSlippage()

            try:
                dt = pd.Timestamp('2006-01-05 14:31', tz='UTC')
                bar_data = BarData(
                    data_portal,
                    lambda: dt,
                    self.sim_params.data_frequency,
                    self.trading_calendar,
                    NoRestrictions(),
                )

                _, txn = next(
                    slippage_model.simulate(
                        bar_data,
                        self.ASSET133,
                        [order],
                    ))
            except StopIteration:
                txn = None

            if expected['transaction'] is None:
                self.assertIsNone(txn)
            else:
                self.assertIsNotNone(txn)

                for key, value in expected['transaction'].items():
                    self.assertEquals(value, txn[key])
Beispiel #6
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    def order(self, asset, amount, style, order_id=None):
        """Place an order.

        Parameters
        ----------
        asset : gateway.assets.Asset
            The asset that this order is for.
        amount : int
            The amount of shares to order. If ``amount`` is positive, this is
            the number of shares to buy or cover. If ``amount`` is negative,
            this is the number of shares to sell or short.
        style : gateway.finance.execution.ExecutionStyle
            The execution style for the order.
        order_id : str, optional
            The unique identifier for this order.

        Returns
        -------
        order_id : str or None
            The unique identifier for this order, or None if no order was
            placed.

        Notes
        -----
        amount > 0 :: Buy/Cover
        amount < 0 :: Sell/Short
        Market order:    order(asset, amount)
        Limit order:     order(asset, amount, style=LimitOrder(limit_price))
        Stop order:      order(asset, amount, style=StopOrder(stop_price))
        StopLimit order: order(asset, amount, style=StopLimitOrder(limit_price,
                               stop_price))
        """
        # something could be done with amount to further divide
        # between buy by share count OR buy shares up to a dollar amount
        # numeric == share count  AND  "$dollar.cents" == cost amount

        if amount == 0:
            # Don't bother placing orders for 0 shares.
            return None
        elif amount > self.max_shares:
            # Arbitrary limit of 100 billion (US) shares will never be
            # exceeded except by a buggy algorithm.
            raise OverflowError("Can't order more than %d shares" %
                                self.max_shares)

        is_buy = (amount > 0)
        order = Order(dt=self.current_dt,
                      asset=asset,
                      amount=amount,
                      stop=style.get_stop_price(is_buy),
                      limit=style.get_limit_price(is_buy),
                      id=order_id)

        self.open_orders[order.asset].append(order)
        self.orders[order.id] = order
        self.new_orders.append(order)

        return order.id
Beispiel #7
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    def test_fill_zero_shares(self):
        slippage_model = FixedBasisPointsSlippage(basis_points=5,
                                                  volume_limit=0.1)

        # since the volume limit for the bar is 20, the first order will be
        # filled and there will be a transaction for it, and the second order
        # will order zero shares so there should not be a transaction for it.
        open_orders = [
            Order(dt=datetime.datetime(2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                  amount=20,
                  filled=0,
                  asset=self.ASSET133)
        ] * 2

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.first_minute)

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEqual(1, len(orders_txns))

        # ordering zero shares should result in zero transactions
        open_orders = [
            Order(dt=datetime.datetime(2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                  amount=0,
                  filled=0,
                  asset=self.ASSET133)
        ]

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))
        self.assertEqual(0, len(orders_txns))
Beispiel #8
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    def test_low_transaction_volume(self):
        # With a volume limit of 0.001, and a bar volume of 100, we should
        # compute a transaction volume of 100 * 0.001 = 0.1, which gets rounded
        # down to zero. In this case we expect no amount to be transacted.
        model = VolatilityVolumeShare(volume_limit=0.001)

        minute = pd.Timestamp('2006-03-01 11:35AM', tz='UTC')
        data = self.create_bardata(simulation_dt_func=lambda: minute)
        order = Order(dt=data.current_dt, asset=self.ASSET, amount=10)
        price, amount = model.process_order(data, order)

        self.assertIsNone(price)
        self.assertIsNone(amount)
Beispiel #9
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 def test_calculate_impact_sell(self):
     answer_key = [
         # We ordered -10 contracts, but are capped at -(100 * 0.05) = -5
         (91485.499914831875, -5),
         (91486.499914830943, -5),
         (None, None),
     ]
     order = Order(
         dt=pd.Timestamp.now(tz='utc').round('min'),
         asset=self.ASSET,
         amount=-10,
     )
     self._calculate_impact(order, answer_key)
Beispiel #10
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 def test_calculate_impact_buy(self):
     answer_key = [
         # We ordered 10 contracts, but are capped at 100 * 0.05 = 5
         (91485.500085168125, 5),
         (91486.500085169057, 5),
         (None, None),
     ]
     order = Order(
         dt=pd.Timestamp.now(tz='utc').round('min'),
         asset=self.ASSET,
         amount=10,
     )
     self._calculate_impact(order, answer_key)
Beispiel #11
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    def test_impacted_price_worse_than_limit(self):
        model = VolatilityVolumeShare(volume_limit=0.05)

        # Use all the same numbers from the 'calculate_impact' tests. Since the
        # impacted price is 59805.5, which is worse than the limit price of
        # 59800, the model should return None.
        minute = pd.Timestamp('2006-03-01 11:35AM', tz='UTC')
        data = self.create_bardata(simulation_dt_func=lambda: minute)
        order = Order(
            dt=data.current_dt,
            asset=self.ASSET,
            amount=10,
            limit=59800,
        )
        price, amount = model.process_order(data, order)

        self.assertIsNone(price)
        self.assertIsNone(amount)
Beispiel #12
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    def test_volume_share_slippage_with_future(self):
        slippage_model = VolumeShareSlippage(volume_limit=1, price_impact=0.3)

        open_orders = [
            Order(
                dt=datetime.datetime(2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                amount=10,
                filled=0,
                asset=self.ASSET1000,
            ),
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[0], )

        orders_txns = list(
            slippage_model.simulate(bar_data, self.ASSET1000, open_orders))

        self.assertEquals(len(orders_txns), 1)
        _, txn = orders_txns[0]

        # We expect to fill the order for all 10 contracts. The volume for the
        # futures contract in this bar is 100, so our volume share is:
        #     10.0 / 100 = 0.1
        # The current price is 5.0 and the price impact is 0.3, so the expected
        # impacted price is:
        #     5.0 + (5.0 * (0.1 ** 2) * 0.3) = 5.015
        expected_txn = {
            'price': 5.015,
            'dt': datetime.datetime(2006, 1, 5, 14, 31, tzinfo=pytz.utc),
            'amount': 10,
            'asset': self.ASSET1000,
            'commission': None,
            'type': DATASOURCE_TYPE.TRANSACTION,
            'order_id': open_orders[0].id,
        }

        self.assertIsNotNone(txn)
        self.assertEquals(expected_txn, txn.__dict__)
Beispiel #13
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    def test_fixed_bps_slippage(self, name, basis_points, volume_limit,
                                order_amount, expected_price, expected_amount):

        slippage_model = FixedBasisPointsSlippage(basis_points=basis_points,
                                                  volume_limit=volume_limit)

        open_orders = [
            Order(dt=datetime.datetime(2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                  amount=order_amount,
                  filled=0,
                  asset=self.ASSET133)
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.first_minute)

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 1)
        _, txn = orders_txns[0]

        expected_txn = {
            'price': expected_price,
            'dt': datetime.datetime(2006, 1, 5, 14, 31, tzinfo=pytz.utc),
            'amount': expected_amount,
            'asset': self.ASSET133,
            'commission': None,
            'type': DATASOURCE_TYPE.TRANSACTION,
            'order_id': open_orders[0].id
        }

        self.assertIsNotNone(txn)
        self.assertEquals(expected_txn, txn.__dict__)
Beispiel #14
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    def _calculate_impact(self, test_order, answer_key):
        model = VolatilityVolumeShare(volume_limit=0.05)
        first_minute = pd.Timestamp('2006-03-31 11:35AM', tz='UTC')

        next_3_minutes = self.trading_calendar.minutes_window(first_minute, 3)
        remaining_shares = test_order.open_amount

        for i, minute in enumerate(next_3_minutes):
            data = self.create_bardata(simulation_dt_func=lambda: minute)
            new_order = Order(
                dt=data.current_dt,
                asset=self.ASSET,
                amount=remaining_shares,
            )
            price, amount = model.process_order(data, new_order)

            self.assertEqual(price, answer_key[i][0])
            self.assertEqual(amount, answer_key[i][1])

            amount = amount or 0
            if remaining_shares < 0:
                remaining_shares = min(0, remaining_shares - amount)
            else:
                remaining_shares = max(0, remaining_shares - amount)
Beispiel #15
0
 def make_order(self, amount):
     return Order(
         self.minute,
         self.asset,
         amount,
     )
Beispiel #16
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    def test_orders_stop_limit(self):
        slippage_model = VolumeShareSlippage()
        slippage_model.data_portal = self.data_portal

        # long, does not trade
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': 100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'stop': 4.0,
                    'limit': 3.0
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[2], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[3], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # long, does not trade - impacted price worse than limit price
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': 100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'stop': 4.0,
                    'limit': 3.5
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[2], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[3], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # long, does trade
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': 100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'stop': 4.0,
                    'limit': 3.6
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[2], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[3], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 1)
        _, txn = orders_txns[0]

        expected_txn = {
            'price': float(3.50021875),
            'dt': datetime.datetime(2006, 1, 5, 14, 34, tzinfo=pytz.utc),
            'amount': int(50),
            'asset': self.ASSET133
        }

        for key, value in expected_txn.items():
            self.assertEquals(value, txn[key])

        # short, does not trade

        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': -100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'stop': 3.0,
                    'limit': 4.0
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[0], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[1], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # short, does not trade - impacted price worse than limit price
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': -100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'stop': 3.0,
                    'limit': 3.5
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[0], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[1], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # short, does trade
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': -100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'stop': 3.0,
                    'limit': 3.4
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[0], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[1], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 1)
        _, txn = orders_txns[0]

        expected_txn = {
            'price': float(3.49978125),
            'dt': datetime.datetime(2006, 1, 5, 14, 32, tzinfo=pytz.utc),
            'amount': int(-50),
            'asset': self.ASSET133,
        }

        for key, value in expected_txn.items():
            self.assertEquals(value, txn[key])
Beispiel #17
0
    def test_orders_limit(self):
        slippage_model = VolumeShareSlippage()
        slippage_model.data_portal = self.data_portal

        # long, does not trade
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': 100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'limit': 3.5
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[3], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # long, does not trade - impacted price worse than limit price
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': 100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'limit': 3.5
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[3], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # long, does trade
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': 100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'limit': 3.6
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[3], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 1)
        txn = orders_txns[0][1]

        expected_txn = {
            'price': float(3.50021875),
            'dt': datetime.datetime(2006, 1, 5, 14, 34, tzinfo=pytz.utc),
            # we ordered 100 shares, but default volume slippage only allows
            # for 2.5% of the volume.  2.5% * 2000 = 50 shares
            'amount': int(50),
            'asset': self.ASSET133,
            'order_id': open_orders[0].id
        }

        self.assertIsNotNone(txn)

        for key, value in expected_txn.items():
            self.assertEquals(value, txn[key])

        # short, does not trade
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': -100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'limit': 3.5
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[0], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # short, does not trade - impacted price worse than limit price
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': -100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'limit': 3.5
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[0], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 0)

        # short, does trade
        open_orders = [
            Order(
                **{
                    'dt': datetime.datetime(
                        2006, 1, 5, 14, 30, tzinfo=pytz.utc),
                    'amount': -100,
                    'filled': 0,
                    'asset': self.ASSET133,
                    'limit': 3.4
                })
        ]

        bar_data = self.create_bardata(
            simulation_dt_func=lambda: self.minutes[1], )

        orders_txns = list(
            slippage_model.simulate(
                bar_data,
                self.ASSET133,
                open_orders,
            ))

        self.assertEquals(len(orders_txns), 1)
        _, txn = orders_txns[0]

        expected_txn = {
            'price': float(3.49978125),
            'dt': datetime.datetime(2006, 1, 5, 14, 32, tzinfo=pytz.utc),
            'amount': int(-50),
            'asset': self.ASSET133,
        }

        self.assertIsNotNone(txn)

        for key, value in expected_txn.items():
            self.assertEquals(value, txn[key])