A data analysis system (1) for displaying data facilitating visual analysis of financial transaction is disclosed. The system includes a transactions database (3) operable to store transaction records (5) defining financial transactions and a processing module (11) operable to determine a hierarchy having a tree structure wherein leaf nodes in the lowest level of the hierarchy correspond to sources and destinations associated with financial transactions represented by transaction records 5) stored in the transactions database (5). The processing module (11) then causes representations of the financial transactions to be displayed on a display screen (13) by determining for each transaction a first set of control co-ordinates comprising co-ordinates associated with elements in a path in the tree structure connecting the source and destination associated with a financial transaction via the closest common parent in the hierarchy common to the source and destination; determining for each transaction a second set of control co-ordinates for drawing a straight line between co-ordinates associated with the source and destination associated with the financial transaction; calculating as a set of control co-ordinates for representing a transaction weighted averages of corresponding co-ordinates in the first and second set, weighted by a bundling factor; and representing each of the financial transactions as a line drawn utilizing the calculated control co-ordinates for each transaction.