I have the following : a sequence of security returns and their probabilities e.g. Security Returns / Probability of Event : 10% Return with 50% probability -5% Return with 10% probability 3% return with 10% probability 15% return with 10% probability I can calculate the mean and the std deviation of the above i.e. E[X] and sqrt of E[X^2] - E^2[X] where E[X] is the sum of probabilities and returns. Given that I have the mean and the std. deviation , I can model the distribution as normal and do further analysis. But is there a way of better fitting a distribution - to take the tails into account - how would I fit the distribution and model(graph) the probability distribution in R And how would I do a monte-carlo for use in simulation that would generate the appropriate distribution [[alternative HTML version deleted]]