Upon completion of the auction, the most recently issued bill, note, or bond becomes on-the-run and the previous on-the-run issue
The most recently issued ten-year Treasury security is referred to as the on-the-run issue
. Once the Treasury issues another (newer) ten-year note, the previously issued note is referred to as the old ten-year note.
The specialness typically peaks around the announcement of the next auction, after which it declines as short positions begin to shift to the next on-the-run issue
.(29) In addition to this regular pattern, other factors influence the specialness of these securities.