Это правило - просто чушь. Информация по FTD берется с сайта SEC, отсюда
https://www.sec.gov/data/foiadocsfailsdatahtm Если вы читаете по английски, то там написано: Fails to deliver on a given day are a cumulative number of all fails outstanding until that day, plus new fails that occur that day, less fails that settle that day. The figure is not a daily amount of fails, but a combined figure that includes both new fails on the reporting day as well as existing fails. In other words, these numbers reflect aggregate fails as of a specific point in time, and may have little or no relationship to yesterday's aggregate fails. Thus, it is important to note that the age of fails cannot be determined by looking at these numbers. In addition, the underlying source(s) of the fails-to-deliver shares is not necessarily the same as the underlying source(s) of the fails-to-deliver shares reported the day prior or the day after.
Можете сами подумать, как это согласуется с "правилом"