I keep getting an error message saying VIXY is not in the index. Is there a way to go about fixing this? Thank you.

`import numpy as np`

from datetime import datetime

import pandas as pd

import math

class VolTrading(QCAlgorithm):

def __init__(self):

self.previous = None

self.position = None

def Initialize(self):

self.SetStartDate(2007,1,1) #Set Start Date

#self.SetEndDate(2018,10,29) #Set End Date

self.SetCash(10000) #Set Strategy Cash

self.AddEquity("SPY", Resolution.Minute)

self.AddEquity("VIXY", Resolution.Minute)

self.SetWarmUp(440)

def OnData(self, data):

history_s = self.History(["SPY"], 2, Resolution.Minute)

last_minute_close_s = history_s.loc["SPY"]["close"][-2]

history_v = self.History(["VIXY"], 2, Resolution.Minute)

last_minute_close_v = history_v.loc["VIXY"]["close"][-2]

self.SPercent = math.log((self.Identity("SPY").Current.Value)/

(last_minute_close_s))

self.VPercent = math.log((self.Identity("VIXY").Current.Value)/

(last_minute_close_v))

if self.IsWarmingUp:

return

if SPercent <= -.01:

if self.position == None:

self.SetHoldings("VIXY", 1)

elif self.position == "SPY":

self.Liquidate("SPY")

self.SetHoldings("VIXY", 1)

self.position = "VIXY"

elif VPercent <= -.01:

if self.position == None:

self.SetHoldings("SPY", 1)

elif self.position == "VIXY":

self.Liquidate("VIXY")

self.SetHoldings("SPY", 1)

self.position = "SPY"