$NYHL index was 643 level on Monday, when ever this index goes beyond 400 level, used to pull back sharply from March 9 TH 2009 onwards ( recent bull market)
When it reaches towards zero line, used to get rally as well.
Index didn't pull back beyond zero line from March 9 TH 2009. !! Until March 2009 index's most of the action was below zero line as well.