Suppose that the short rate is currently at 2% and its standard devia- tion is 2% per annum. What happens to the standard deviation when the short rate increases to 5% in the Vasicek model? Suppose that the short rate is currently at 2% and its standard devia- tion is 2% per annum. What happens to the standard deviation when the short rate increases to 5% in the Vasicek model