# Autocorrelation of daily time-series using acf and pacf plots

I have a time series dataset with daily entries over the past 20 years.

I would like to see whether the series is autocorrelated.

To do so I have done the following>

dataset=read.csv(file="https://dl.dropbox.com/u/22681355/dataset.csv", head=TRUE)
par(mfrow=c(2,1))
dataset=diff(dataset)
acf(dataset)
pacf(dataset)


From the plots it seems that there is no autocorrelation, however, I'm not sure whether the acf and pacf plots are suitable for my dataset.

What is a suitable test for stock data ?

-