I am using a spreadsheet to analyze and compare various future trading systems. I've tapped out my Excel ability and was hoping some expert users could help me with a more specialized formula. The problem comes in my "running total" column which adds the individual system results together for each trading day and compares that to the total from the prior trading day. If the total is positive the cell is colored blue and if negative it is red and the new running total amount is displayed... this all works fine.

Where I need help is I'd really like to measure the size of each "drawdown" and list the top 5 or 10 drawdowns for evaluation. I just don't know how to write a formula that will keep track of the consecutive negative days and add them together for output in specific cells. I know it is a measurement of how far the value drawdowns from previous/last high value but I am WAY over my head with the calculation.

Any help would be greatly appreciated.