The sky is falling, at least according to the Daily Mail.

On Tuesday, the Dow Jones Industrial Average (^DJI -0.53%) suffered its worst single-day performance since Donald Trump was elected in November. The index "tumbled," as the Daily Mail put it, by 238 points.

A worried investor looking at a plunging stock chart.

Image source: Getty Images.

It's not entirely clear what caused the Dow to put up a triple-digit loss, but most Wall Street pundits have pointed to the Trump administration's inability to progress the American Health Care Act (AHCA) through Congress as the culprit. Repealing and replacing the Affordable Care Act, the hallmark healthcare legislation of former President Barack Obama, was viewed as Trump's first major task as president, and the AHCA's inability to gain traction in Congress thus far has clearly sent jitters throughout the market. It's also heightening fears that subsequent legislation, such as corporate income-tax reform, may be further out than some had counted on.

The Dow didn't really "tumble" 238 points if you put everything into context

But regardless of the reason for Tuesday's drop in the market's most iconic index, one thing is crystal clear: It wasn't a "tumble," a "plunge," or even anything to get remotely worked up about.

Sure, 238 points might sound like a big number, but consider where we've come from. In March 2009, during the lows of the Great Recession, the Dow Jones was clinging to the 6,500-point mark. Eight years later, the Dow had touched 21,000. Nowadays, a 238-point "tumble" equates to the Dow losing just 1.1% -- a pretty pedestrian move that has happened countless times before.

A list of the top-20 largest point and percentage declines in the Dow.

Data source: Wikipedia, The Wall Street Journal, Dow Jones. Table by author. 

Furthermore, a 1.1% loss in the Dow doesn't even come close to registering among the worst days the index has seen. Just to crack into the top 20 percentage declines of all-time, the Dow would essentially need to fall 7%, which works out to more than 1,400 points. Now that would qualify as a tumble. A 238-point, 1.1% decline is wholly forgettable.

Buy-and-hold remains your best strategy for success

Tuesday's dip in the Dow Jones is a great reminder to investors that stock market corrections are a completely normal part of investing. According to data from Yardeni Research, the broad-based S&P 500 (^GSPC -0.54%) has undergone 35 stock market corrections of at least 10% since 1950. This works out to an average of one correction every two years or so. Even more noteworthy, however, is that whether it takes weeks, months, or years, a bull market rally always winds up erasing the full extent of a correction -- 35 for 35. There really aren't any better odds than that.

A separate finding from J.P. Morgan Asset Management confirms that buying and holding over the long term is truly the best strategy for success. J.P. Morgan examined the best and worst single-day performances of the S&P 500 over a 20-year period (Jan. 3, 1995 through Dec. 31, 2014) and found that holding throughout the ups and the downs generated the best returns.

An investor holding a stopwatch in front of a growing stack of coins, signifying the power of compounding over time.

Image source: Getty Images.

For example, despite weathering both the dot-com bubble and the Great Recession, long-term investors in the S&P 500 have realized a return of 9.9% per year, or 555% overall. However, if they missed just 10 of the best days over this 20-year period (that's more than 5,000 trading days total), their gain dropped by more than half. Miss a little more than 30 of the best days, and their gains would disappear entirely!

In other words, stock market corrections and 238-point plunges in the Dow aren't anything you need to be afraid of. If anything, regular dips in the stock market serve as a great opportunity to pick up high-quality stocks that have been discounted over the short term, even as their long-term growth outlook remains intact. Keep your emotions in check and use days like Tuesday to look for high-quality companies being valued cheaply.