It is well known that circuit breaker rules and technical glitches can shut down stock markets, and they do so for a day at most (e.g. via NYSE rule 80B). Natural disasters (e.g. hurricanes) and major events (9/11) can shut down markets for a few days.

But, can the stock market be shut down for an extended period of time, i.e. weeks or months? Historically, the answer is yes: According to "What Does It Take to Close the Stock Market?" (Kevin Chupka, 2012) the longest NYSE shutdown was at the beginning of WWI in 1914 for more than 4 1/2 months.

This leads to the question. Is it possible to assess the economic implications, and therefore the feasibility, of such a long-term shutdown of the stock market, today?

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    Here's an implication that concerns me today. I have a number of long stock positions protected by deep in-the-money longs puts which have been preventing additional losses for some time. For example, a $44 stock with long $40 puts (worth $15 now) with the stock now at $25 (net loss of $4). I was hoping to ride these positions down until the market settles down and then sell the puts, lowering my cost basis which is $4 higher than current price. If the market is shut down, I would hope that I could still exercise them to sell the stock but I don't know for a fact. May have to exercise now Mar 16, 2020 at 11:37
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    @BobBaerker It's not clear to me how stock options should/would be handled when an option expires within a stock market shut down.
    – mcmayer
    Mar 16, 2020 at 11:47
  • it's quite a good point - a chilling point - that derivatives would be a nightmare in a shutdown :/
    – Fattie
    Aug 13, 2020 at 21:00

2 Answers 2


For the sake of putting in an answer:

It's incredibly unlikely the major markets would shut down for more than a day or two for any reason.

Note that, of course, one can ask truly cataclysmic questions such as "will the USG go absolutely broke and cease to exist?" or "In the UK will the military stage a coup?" or "Will an asteroid crush the planet?"

Of course in each case you could say "there's a slight chance."

Barring incredibly major ELE disasters, the major exchanges won't close for periods over a day or two.

Note that: say the US suffers hyperinflation. That won't happen literally overnight. It will be an orderly disaster over a few months.

I don't really think any answer is possible here other than "Based on a clear view of 200 years of history, it's incredibly unlikely they would 'dramatically close for a long period.'"


It would be bad for the economy to shut down the market. First, trading financial products is big business. With most trading electronic why shut the market and directly harm economic output? Second, functioning markets are important to companies conducting business with one another. By shutting the market you're harming that process and making it more difficult. You could estimate the first directly. The second would be extremely more difficult.

I've yet to hear a good reason for shutting down the market. Your question implies that maybe you have a reason in mind. Do you mind sharing it?

For more detailed info see my response here to a similar question: What would be the effect of closing stock market trading for two months to Coronavirus?

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    I'm sure all the committees are buzzing with ideas and there certainly is political pressure to "do something". Unfortunately, politics does does not always reason perfectly, and that is my reason for considering it. I.e. I'm just trying to do my own analysis in order to determine whether this is a scenario to consider.
    – mcmayer
    Mar 17, 2020 at 8:06
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    It's a natural question to ask, and it's only with lots of financial market experience, and having lived through the GFC, that one comes to the "correct" conclusion. It may happen again, I just think it's more likely to be from a war or cyber-attack than this virus. You're right about the buzz, some politicos have definitely asked chairmans of exchanges/regulatory bodies and such if they should shut the markets in addition to the schools. Mar 17, 2020 at 23:02

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