PAYEMS monthly delta and S&P500

plot(to.monthly(SP5)[kikan][,1],axes=T)
par(new=T)
plot(diff(PA[kikan]),axes=F,ylim=c(-900,900),col=3)
par(new=T)
plot(rep(0,length(PA[kikan])),col=2,ylim=c(-900,900),axes=F,type='l')