The dynamics are familiar: The economy is strong and about to enjoy a boost from the implementation of the GOP's recently passed tax cut plan, inflation remains tepid, the Federal Reserve's rate hike campaign is proceeding cautiously, and corporate earnings growth has been solid. According to Jeff Hirsch at the Almanac Trader, this performance along with the solid run to end 2017 suggest the new year will be a great one for investors. Jason Geopfert at SentimenTrader notes that the gains are part of a globally synchronized market with "extreme momentum" on display.