There was  more lasting impact from the North Korean nuclear test on Sunday, Sept. 3, which was its most powerful to date. When markets opened that Monday, the yen immediately jumped 0.9 percent. By the close in New York, it was up 0.5 percent, surrendering some of that initial advance. The currency went on to gain further that week as Hurricane Irma threatened major damage to Florida.

Taking a broader look, the gains for haven assets so far on Friday are well short of the reactions on Aug. 29, when North Korea launched an intercontinental ballistic missile over Japan. And they pale in comparison to the surges seen a week ago when traders were fearful that the weekend would bring missile tests, and that Florida would suffer much more damage than it did from Irma.

“Markets won’t like it, but I don’t think it’s necessarily the precursor to a sustained market pullback,” James Soutter, a portfolio manager at K2 Asset Management in Melbourne, said about Friday’s missile launch.

Mark Mobius, the veteran emerging-market investor who is executive chairman at Templeton Emerging Markets Group, in May put the North Korea threat in these terms: “there’s nothing you can do about it -- if something breaks out, we’re all finished anyway.”

The implication of that analysis is that some sort of actual conflict, such as a US shoot-down of a North Korean missile, might be needed to trigger a sustained impact on markets. (Bloomberg)