Editor’s Note: David A. Andelman is a visiting scholar at the Center on National Security at Fordham Law School and director of its Red Lines Project. He also is a contributor to CNN and a columnist for USA Today, and author of “A Shattered Peace: Versailles 1919 and the Price We Pay Today.” He was a foreign correspondent for The New York Times and CBS News in Asia and Europe. Follow him on Twitter @DavidAndelman. The views expressed in this commentary are his.

CNN  — 

Donald Trump is suddenly learning a very hard lesson. Stock markets that go up can, quite suddenly and precipitously, go down. And then there’s the other half of that lesson. When you buy the good news, you inevitably own the bad as well.

That’s the stunning conclusion from Monday’s largest single-day drop in the history of the Dow Jones Industrial Average – 1,175 points in one day, or 1,841 points in the last two trading days. In percentage terms, that’s the biggest drop since the 2008 financial crisis.

For the major indexes, Monday’s market plunge wipes out the entire gain for this year – a gain the President pats himself on the back for almost every day. For perspective, more than a trillion dollars in total value has been wiped off the books and out of the hands of American investors, retirees and anyone with a 401(k) or IRA.

There’s more to this than meets the eye. It’s also the first day on the job of the new chairman of the Federal Reserve, after a weekend when his predecessor, Janet Yellen, let it be known she was most disappointed in not getting a second term from Donald Trump. The markets might have wanted to have a more experienced hand on the tiller at the moment.

It was quite a roller-coaster day, one that tries even the most stolid souls. But Trump, who spent the afternoon in Blue Ash, Ohio, trumpeting his economic and tax plan and all it is doing for the average American, did not say a single word on what was happening 650 miles to the east at the New York Stock Exchange.

Without a doubt, the President is having to digest this remarkable news. It might be tough for a New York real estate mogul, accustomed to selling his luxury high-rises to corporate tycoons and global investors through good times and bad.

And there were many pundits on Wall Street prepared to suggest this could well be a brief, one-time event – a “flash crash,” as James Cramer suggested on CNBC before the market close.

But days like Monday can certainly feed on themselves. Many, turning on the evening news Monday night or checking their 401(k) balances Tuesday morning, could well believe the end is nigh and only compound the panic by deciding to sell the mutual funds in their 401(k)s.

While the downdrafts of the past two trading days could be laid at the feet of institutional investors, as early as Tuesday, small investors could begin unloading their mutual funds. This would force fund managers to sell stocks they might otherwise have held in order to raise cash to satisfy the redemptions. Such forced sales could then continue compounding the downward market spiral.

Still, there are some signs of hope on the horizon. First, such a dramatic turn on Wall Street could slow plans by the Federal Reserve to continue raising interest rates this year, though the new Fed chairman, Jerome Powell, kept judiciously silent on Monday. Rising rates can have a depressive effect on the stock markets, affecting corporate profits and suggesting to some investors they can do better selling their stocks to buy bonds.

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    And then there is the reality Trump must confront. The economy and stock markets don’t always move in lockstep – and that can be a good thing. Corporate earnings and economic growth have not been this good in a long time – and, so far, they show no signs of weakening.

    It also seems unlikely a recession is on the horizon. At least, that’s the last glimmer of hope we may hold onto, until the markets, as they inevitably will, turn upward again.