Financial Time Series

If there were some linear predictability, i should be able to exploit that to make money in the marketye. Another one of those properties that really caught my attention is the volatility clustering. That unlike some unifort of pure gausyand random noise, when there are outliers, those outliers tend to a kind of cluster or com on groups. It's a characteristic that it's present in a lot of financial time series, but you can't really explain it.