1/CHAOS FOR CHRISTMAS

Donald Trump's U.S. presidency has lurched from crisis to crisis since he took office, but turbulence is reaching new highs just in time for Christmas.

The resignation of Defense Secretary James Mattis after a major reshaping of the superpower's global military footprint has grabbed headlines, coming on the heels of other high-profile departures and as investigations into Russian ties to Trump's inner circle comes to a head.

For markets, there is a more immediate threat. A row over funding Trump's Mexican border wall could soon cause a partial government shutdown; a more serious closure looms in September when rainy-day money runs out.

And that's happening as Wall Street endures its worst December since 1931 and a flattening bond yield curve signals tough times for the economy. There will be plenty of events that offer a sneak preview into how 2019 will shape up. A hefty bond sale program will test investors' appetite for U.S. debt while consumer confidence and home sales data will show whether recent yield curve moves are justified - and if they are set to go further.

- U.S. House passes funds for Trump wall; government shutdown looms

- U.S. defense chief Mattis quits after clashing with Trump on policies

- Part of the U.S. yield curve just inverted; what does that mean?