Even after some pretty significant events concerning Iran the U.S. stock market shrugged off the tension. It helps that President Trump seems to be playing down the confrontation by being cautious with his response. It also helps that our economy appears to be bouncing back from weakness seen in the summer months extending into the last quarter of 2019.
Maybe the market recognizes that the Iran issue is too small of an event to make any difference in the world economy. The bigger event, central banks are already taking a very loose money stance thus boosting economies around the world. Our Fed has also taken that same stance.
Regardless so far the Iran issue is a non-event for our stock market.