S&P Bear Warning Indicator
// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © gary_trades

//THIS SCRIPT HAS BEEN BUIL TO BE USED AS A S&P500 SPY CRASH INDICATOR (should not be used as a strategy).
//THIS SCRIPT HAS BEEN BUILT AS A STRATEGY FOR VISUALIZATION PURPOSES ONLY AND HAS NOT BEEN OPTIMISED FOR PROFIT.
//The script has been built to show as a lower indicator and also gives visual SELL signal on top when conditions are met. BARE IN MIND NO STOP LOSS, NOR ADVANCED EXIT STRATEGY HAS BEEN BUILT.
//As well as the chart SELL signal an alert has also been built into this script.
//The script utilizes a VIX indicator (marron line) and 50 period Momentum (blue line) and Danger/No trade zone(pink shading).
//When the Momentum line crosses down across the VIX this is a sell off but in order to only signal major sell offs the SELL signal only triggers if the momentum continues down through the danger zone.
//To use this indicator to identify ideal buying then you should only buy when Momentum line is crossed above the VIX and the Momentum line is above the Danger Zone. 
//This is best used as a daily time frame indicator

//@version=4
strategy(title="S&P Bear Warning", shorttitle="Bear Warning", pyramiding=0,
 currency=currency.USD, default_qty_type=strategy.percent_of_equity, default_qty_value=100,
 initial_capital=1000, commission_value=0.1)

//Momentum
len = input(50, minval=1, title="Length")
src = input(close, title="Source")
bandUpper = input( 5)
bandLower = input(-5)
// ————— Control plotting of each signal. You could use the same technique to be able to turn acc/dist on/off.
showVixFix = input(true)
showMomentum = input(true)
 
mom = src - src[len]
myAtr = atr(14)
plot(showMomentum ? mom : na, color=color.blue, title="MOM")
plot(showMomentum ? 0 : na, color=color.silver, title="MOM Zero line", style=plot.style_circles, transp=100)
plot(showMomentum ? myAtr : na, color=color.orange, title="ATR", transp=90)
 
//VIX
VIXFixLength = input(22,title="VIX Fix Length")
VIXFix = (highest(close,VIXFixLength)-low)/(highest(close,VIXFixLength))*100
plot(showVixFix ? VIXFix : na, "VIXFix", color=color.maroon)
 
band1 = plot(showVixFix ? bandUpper : na, "Upper Band", color.red, 1, plot.style_line, transp=90)
band0 = plot(showVixFix ? bandLower : na, "Lower Band", color.red, 1, plot.style_line, transp=90) 
fill(band1, band0, color=color.red, transp=85, title="Background")
 
//Identify Triggers
//Back Test Range
start = timestamp("America/New_York", 2000, 1, 1, 9,30)
end   = timestamp("America/New_York", 2020, 7, 1, 0, 0)

//Momentum 
Long1 = mom > bandUpper
Short1 = mom < bandLower
 
//VIX
Long2  = crossover(mom, VIXFix)
Short2 = crossunder(mom, VIXFix)

//Warning Alert
SellAlert = Short1
alertcondition(SellAlert, title="Sell SPY", message="Warning Selling off {{ticker}}, price= {{close}}") 

//Entry and Exit
if time >= start and time <= end
    strategy.entry("SELL", false, when = Short1)
 
strategy.close("SELL", when = Long2)