This dissertation consists of five papers concerned with the estimation and analysis of financial price processes. The first paper develops a stock price model and analyzes the impact of the US and the regional European stock markets on the local European countries’ stock markets. Among several things, we find that the dependencies among the stock markets do not increase during periods of distress. The second paper investigates the spillover from the US and Japanese stock markets to the local stock markets in the Pacific Basin region and China using the model in the first paper. We find that identification of jumps can be important for portfolio reallocation. Further, on most occasions the spillovers from jumps are not higher than spillover...