The Erosion file is a text file which may be used by firms to calculate the cash adjustment for the three NYMEX Electricity contracts where the contract values change during the spot month. Those products are the PJM Peak Calendar-Month LMP Swap (JM), Northern Illinois Hub Peak Monthly Swap (UM), and AEP Dayton Hub Peak Monthly (VM). The file contains the current number of peak days for the contract, the data necessary to calculate the pending and final erosion values and the number of peak days for the next day.
On November 16, 2009 CME Clearing will begin posting the Erosion file generated by Chicago in the CME directory, ftp.cmegroup.com/pub/span/data/cme, on ftp.cmegroup.com. The New York generated file will still be located in the existing NYMEX directory, ftp.cmegroup.com/pub/span/data/nym. The file name for the Chicago generated file will be in the same format as the current production file: nym.erosion.YYYYMMDD.txt. As an example, the file for November 13, 2009 would be named: nym.erosion.20091113.txt
CME Clearing has been parallel testing the files for several months. The file formats of the two files are guaranteed to be identical and there are no major data differences between the two files. Firms should begin conversion to the new file location as soon as possible. CME Clearing will stop publishing the file in the ftp.cmegroup.com/pub/span/data/nym directory on December 4, 2009.