Lawmakers can't find the votes to keep government open

US politicians failed to reach a deal to keep the government open late on Friday night and a government shutdown began on Saturday.

Republicans and Democrats frequently toy with a shutdown but the is the first one since 2013 when a shutdown continued for 16 days.

The timing is significant as Saturday is also the one year anniversary of Trump's inauguration.

"Democrats are far more concerned with illegal immigrants than they are with our great military or safety at our dangerous southern border," Trump said on twitter. "They could have easily made a deal but decided to play shutdown politics instead."

The market scoffed at the threat of a shutdown on Friday and the S&P 500 closed at an all-time high. The US dollar also finished near the best levels of the day.

The market has seen this game before so it's likely to take it all in stride, at least for awhile. The US dollar might be more vulnerable in the near term.

Here's what Commerzbank wrote on Friday.

Here is how the S&P 500 performed during previous shutdowns. Note how the past three haven't hurt the market but that also may include the final day or two of a shutdown when a deal was imminent.