For some Americans’ finances, the Iran war was over almost as soon as it began. Those with access to stocks — a majority of Americans have some, though the ultrawealthy have most — saw the S&P 500 dip about 8% when the war started, only for it to bounce 19% starting in late March, more than making up its losses. The index is now up 10.7% for the year, which if it held would make for the fourth consecutive year of double-digit stock increases.

President Donald Trump has been quick to trumpet these gains. “We have 401(k)s at their all-time high, highest they’ve ever been, and that…