Here's the indicator for bonds
study("AK FTM indicator_Bonds")
len = input(85,title = " # days")
R2 = security("TLT","D",roc(close,len))
R1 = security("SPY","D",roc(close,len))
sell = (R1 > R2)
buy =(R2 > R1)
plot(R2,color= blue,linewidth=2,title="BOND")
plot(R1,color= purple,linewidth=2,title="EQUITY")
bgcolor(buy ? lime:red)