Here is my forecast for 2017, based on past first years in the presidential term going back to 1953. The problem with the first year of a presidential term is there have been some very good first years (1989, 1997, 2013) and very bad first years (1957, 1973). When you average them together, you get a ho-hum forecast for 2017, which shows a mild upward bias (grey line in chart).
There is a silver lining though. If you apply a simple filter to the data, the forecast gets more interesting. It turns out that the first 5 trading days of the year provide a good early indication of how the market will perform the rest of the year. If the SPX is positive after the first 5 days of trading, the market should experience a strong rally of 15% on average (blue line in chart). If the SPX is down in the first 5 trading days, the market is expected to finish the year with a small loss of 4% on average (red line). The key is where the SPX closes on Jan 9 relative to the Dec 30 close at 2238.83. It will provide a good indication of what to expect in Trump's first year as president.
Happy New Year! Best wishes for a profitable year in 2017.