How has the S fund performed during January when a new President is inaugurated? 
I now have a full 30 years of monthly data going back to January 1987, so I can answer that.  Here's the January returns for the last four Presidents: 
1989 – George H.W. Bush:   F +1.27%, C +7.14%,S+5.48%, +1.76%
1993 – Clinton:                       F +1.88%, C +0.86%, S +2.18%,I -0.12%
2001 – George W. Bush:       F +1.65%, C +3.55%, S+5.44%, I -0.05%
2009 – Barrack Obama:       F -0.86%, C -8.41%, S -8.19%, I -11.93%
That’s not a lot of data to go by, and the ugly climax to the 2007-09 bear market skews the results. Hard to draw any conclusions other than it’s a bad month for the I fund.