  We propose a simple stochastic volatility model which is analytically
tractable, very easy to simulate and which captures some relevant stylized
facts of financial assets, including scaling properties. In particular, the
model displays a crossover in the log-return distribution from power-law tails
(small time) to a Gaussian behavior (large time), slow decay in the volatility
autocorrelation and multiscaling of moments. Despite its few parameters, the
model is able to fit several key features of the time series of financial
indexes, such as the Dow Jones Industrial Average, with a remarkable accuracy.
