Despite a net monthly gain, along with a new historic high of 2134 for the sp'500 in May, underlying momentum is continuing to swing (if slowly) back toward the equity bears.
Underlying MACD (blue bar histogram) has started a new month by ticking lower again, and is now negative cycle for the fourth consecutive month.
Even if renewed strength to the sp'2160/80 zone in mid/late June, momentum will remain moderately negative, and certainly favours the equity bears.
A sig' retrace for US/world markets looks due this summer/early autumn.
From there, renewed upside into 2016.. and probably all the way into 2017 looks probable.