None of the 2018-2019 stock market ups and downs are even remotely close to making the list of 20 biggest percentage gains or drops. (Shannon Stapleton/Reuters)

Stocks are certainly off to an interesting, exciting and unnerving start for the year. We’ve got big point swings — like the Dow’s 660-point drop on Thursday and its 747-point gain Friday.

We’ve gotten dramatic negative news, such as Apple announcing that iPhone sales in China will be below expectations, which triggered a 10 percent drop in its stock price and accounted for 107 points of Thursday’s Dow decline.

Then Friday, we got positive news about job creation and word that the Fed may slow down rate rises — cited as reasons for the boost the market got.

If you believe that markets are rational every day, stocks were telling us on Thursday that doom was drawing near, and Friday was a new dawn. Good luck making sense of that.

Add to these wild ups and downs — which I called whiplash in a column two months ago — the fact that President Trump has attracted far more attention to the market than it would normally get.

He took credit incessantly when stocks were going up, and then incessantly blamed the Federal Reserve and everyone and everything but himself for the decline when shares began falling. Trump’s dueling followers and foes have added media noise to the statistical noise by crediting or blaming him for whatever stocks happen to be doing.

But let’s set politics and the blame game aside. Instead, let’s talk about what I think is what really matters to those of us who are nonprofessional investors or would-be investors: How should we deal with what’s going on?

Sure, I’d love to be able to tell you whether stocks will rise or fall from here and what, if anything, the financial markets are telling us about the economy. But I don’t know those things, and no one knows.

What I can do, though, is to try to put things in perspective, based on my decades of writing about markets, supplemented by recent conversations with market mavens and statistical types.

The first thing you need to know is that big scary Dow down numbers or big happy Dow up numbers don’t necessarily tell you all that much.

The Dow Jones industrial average is based on the share prices of a mere 30 stocks. Almost no investor money is tied to the Dow’s performance, while trillions are tied to the Standard & Poor’s 500 index. Which, as its name implies, is based on the market values of its 500 or so components.

But the Dow has huge mindshare. That’s why people talk about it so much, and why I’m writing about it.

Because the Dow is so much higher than it used to be — as recently as 1980, it was below 1,000 — its point moves are obviously bigger than they were. And big point moves make for big headlines.

Take Thursday’s drop, the 12th largest daily in point terms (according to Wikipedia) since the Dow was created in 1896. But that drop was considerably less than 3 percent, which isn’t remotely close to a 12th-largest huge percentage drop, which was 7.7 percent.)

Or take Friday’s gain, the fourth-largest ever in point terms but only 3.29 percent, less than a third of the Dow’s fourth-largest percentage rise of 11.36 percent.

Even better, take the Dow’s first four-digit daily gain, posted the day after Christmas, the first trading day after the Dow’s big Christmas Eve drop. That gain understandably got lots of attention.

But at 4.98 percent, the Boxing Day uptick wasn’t remotely close to a Dow record in percentage terms.

Howard Silverblatt, senior index analyst at S&P Global, told me that the Dow has posted daily gains of at least 5 percent 65 times in its history. So Boxing Day’s gain was a point record, but not remotely a percentage-gain record.

(The Dow, Silverblatt said, has gone down more than 5 percent 76 times. That’s something to keep in mind the next time there’s a big point drop.)

Let me expand on this points-versus-substance concept a bit. According to Wikipedia, a majority — 11 — of the 20 biggest daily point drops in the Dow’s 122-year history have taken place since the start of 2018. As have nine of the 20 biggest Dow gains.

But none of the 2018-2019 ups and downs are even remotely close to making the list of 20 biggest percentage gains or drops.

You’ve heard, of course, that last year was the worst stock market year since the Great Recession. But how bad was it? Not so terrible, if you remember that index fund investors get dividends in addition to whatever gains or losses posted by the index.

For example, Vanguard says, every $1,000 you had in its Admiral class S&P 500 index fund at the start of the year was worth $947.81 at year-end. That’s an overall drop of a tad above 5 percent — not the end of the world. December was a really, really, REALLY bad month — but you ended up with $909.67 of your $1,000. A creepy number, but not the end of the world, either.

Tempting as it is to blame or credit Trump for the stock market, he’s only part of the story, and something we’ll deal with another day.

The big factor in the huge day-to-day swings that we’ve been seeing is that most stock trading is computer-to-computer, with zero, or minimal, input from human beings.

Momentum is a huge factor in the computerized trading formulas. This means that although financial fundamentals determine what happens in the long run, computers have lots of influence in the short or intermediate run. So stocks go up because they’re going up, and down because they’re going down.

Does the market’s recent drop presage a recession, as many people are predicting? Not necessarily. The S&P 500 is only one of the 10 components of the Conference Board Leading Economic Index, and that index itself is far from infallible.

If you’ve got financial staying power, a reasonably long horizon and a strong stomach, you can ignore the ups and downs and ride this out. If you don’t have the staying power or the stomach to deal with wild ups and downs, maybe you shouldn’t own stocks. And that, my friends, is the bottom line.