In the morning report, we said equities have been sideways to down in the last week of the month since August 2009.  More precisely, it is the week that coincides with the long term Treasury auctions in the 2, 5 and 7 year tenors that tends to exhibit this behavior.  Usually, this is the last week, but not always.  The first of the auctions is the 2 year, which usually occurs on a Tuesday, but sometimes a Monday due to holidays.  Below highlights 2 year auction dates in magenta.  In addition, FOMC Announcement dates are highlighted in cyan.  With an announcement scheduled for next Wednesday, it is also instructive to look at the two occurances (in September 2009 and January 2010) when there was an announcement in an auction week.  This gives next week a bearish seasonality until the last of the auctions, the 7 year, is over on Thursday.  GDP on Friday could be a catalyst for a continuation of the rally, however. 

As always, seasonalities should be taken with a grain of salt as any number of other factors can override.