One of Sherlock Holmes’s most famous pronouncements was that “when you have eliminated the impossible, whatever remains, however improbable, must be the truth.” His point was that far too many of us dismiss what’s highly unlikely as impossible, when of course it isn’t – as this presidential race has shown us at least once a week for the past year. With that in mind as the race rounds blessedly into the home stretch, let’s imagine a few highly improbable yet hardly impossible campaign events that could affect the stock markets, the economy, Congress, and our own lives.

  1. A devastating Hillary Clinton email surprise. This one isn’t even all that improbable. With potentially thousands more emails and other documents scheduled to be released by court mandate before November 8, and WikiLeaks founder Julian Assange promising to release “significant” Clinton documents, plus whatever the Russians may have stockpiled from their apparent raid on the Democratic National Committee servers, who knows what might be in there?
  2. Donald Trump commits an ultra-gaffe in a debate. It’s likely yet unlikely – he constantly says things that would doom any other candidate, but he has so inured us to outrageousness that we’re rendered almost unshockable. But “almost” is not “entirely,” as Holmes would note, and Trump could still cross some line that effectively decides the election weeks in advance.
  3. Voters turn out to have been lying to pollsters. Politicos parse two-point movements in poll results, but mounting evidence suggests that political polling is becoming less accurate. It may be significant that U.K. pollsters mis-called the strength of the Conservatives’ victory in May 2015 and the outcome of the Brexit vote this summer – significant because one explanatory hypothesis (among many) is that pollsters are for some reason not picking up right-leaning sentiment. Meaning Trump could be stronger than anyone supposes.
  4. Trump loses and disputes the outcome. A challenge seems unlikely if he loses big, but he has seeded the ground by stating that the only way he could lose is if the election is rigged. Remember that this is a man for whom no epithet is more damning and unbearable than “loser.” If he attracts more votes than anticipated and loses narrowly (see above), a legal challenge could create a crisis of uncertainty.
  5. Investors, freaking out as one or more of these possibilities becomes less improbable, bail out of stocks for the security of cash or gold. The market therefore sags or maybe tanks. The fear feeds on itself. The next recession, waiting just offstage after 7 ½ years of sluggish expansion, makes its entrance.

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Obviously all of these scenarios are highly improbable, but any of them is at least barely possible. Which one is most worthy of our concern? As Holmes also said, “I never guess. It is a shocking habit — destructive to the logical faculty.” So I won’t guess about them either. But I will keep an eye out for hints that any of them just might be more than merely possible.