Legendary investor Warren Buffett has often said that he makes investment decisions as if the market would close for the next five years immediately after buying stock in a company. He goes on to explain that if he decides he likes a company and believes in its long-term growth prospects, then he would have no interest in selling it before then anyway, and would rather not be distracted by the daily gyrations of the market.

But based on the way anxious investors reacted to Wednesday’s nearly four-hour halt of the New York Stock Exchange, apparently many of them can’t stomach the idea of the market closing at all. For many people day-trading has become a way of life, overcome by the temptation of making a living without ever leaving the house.

Also feeling the pinch of the unexpected interruption were so-called high-frequency traders, who skim fractions of pennies off of very large orders. I can’t imagine very many people outside Wall Street feel much sympathy for them, but the fact of the matter is they have become an integral component of the stock market trading ecosystem.

Over the course of my 28-year career as a stockbroker I never engaged in day trading or high-frequency trading, but I can imagine having the market close suddenly and unexpectedly with open positions fully exposed would be extremely nerve-wracking. The good news in this case is that trading continued on all of the other major exchanges, so to a large degree those open positions could be offset elsewhere to mitigate any losses that might occur.

However, sometimes all the exchanges close simultaneously, leaving very limited alternative for hedging your bets. You may recall in the aftermath of the 9/11 attacks the entire U.S. stock market shut down for a week to prevent an onslaught of panic selling that might have led to a full blown market meltdown. By the time the market reopened most folks had concluded that the financial consequences of that tragedy were minimal with respect to the overall economy.

That hunch proved correct when the stock market recovered to its September 10^th levels less than two months later. As for this week’s shutdown, the following day the market regained most of what it lost the prior day. Neither of which necessarily proves anything, but both of which suggests that Mr. Buffett’s approach makes a lot of sense in light of the increasing frequency and intensity of cyber-attacks on financial institutions and other threats to the global financial system.

So with all of that in mind, this may be a good time to review your portfolio to determine the extent to which it is “shock proof”. If the worst happened and you were stuck with your current portfolio for weeks or months, would you be content to sit with what you have? If not, then what is it about those holdings that require the market to always be open in order for you to feel comfortable holding them?

Subscribers to our Personal Finance newsletter service have access to more than a dozen free Special Reports, including one titled “Five IDEAL Stocks for Any Market”, which I wrote and is essentially a mini-portfolio of stocks I’d feel comfortable holding if the stock market shut down for the next five years. That’s not to say that they are necessarily the ones that I feel will perform the best over that period of time, but rather have the best chances of performing well under a variety of economic conditions.

We all know some companies and industries are more sensitive to changes in the economy than others. For the better part of the past year the energy sector has experienced upheaval as the price of oil has dropped in half. For those energy companies that are over-leveraged and cannot generate a profit at current prices the outcome may be disastrous, while for their better capitalized competitors it may prove an opportune time to acquire assets at fire sale prices.

For that reason I have an oil company – Chevron – listed first in my mini-portfolio of stocks for any market. It also includes a global insurance company, a large U.S. bank, a major telecomm provider, and   a computer chip manufacturer. The average dividend yield for these five stocks is 3.8%, about a half-percentage point greater than the current yield on a 30-year Treasury bond.

I would be perfectly happy to hold onto all of these companies if the stock market closed for the next five years, much less the next five hours. And like Buffett, I would only sell one of those stocks if something critical changed in a way that fundamentally altered their long-term value proposition. Not only is that a good way to generate consistent long-term profits, but it’s also a great way to avoid worrying about the daily ups and downs of the stock market.