The Dow Jones Industrial Average hit its latest milestone on Wednesday: 22,000. Photo: Getty Images 
 
 The Dow Jones Industrial Average has been shattering record after record lately. Barely six months after it crossed the 20,000 mark, the Dow hit 22,000 on Wednesday morning, before pulling back slightly. It’s another milestone that might not mean much for your portfolio, but it is symbolic of the enormous bull run the market has enjoyed since 2009. 
 
 Here’s some background on the Dow and what’s driven it to such soaring heights: 
 
 What is the Dow Jones Industrial Average anyway? 
 
 The Dow is the oldest and most-widely followed U.S. stock market index, composed of 30 large public companies. Meant to represent a broad cross section of the market, the index is composed of a diverse group of blue chip companies such as Pfizer, Boeing, Coca-Cola, Goldman Sachs, Walmart, and Disney. 
 
 Get the best of Barron's Next every weekday. By signing up, I agree to the Privacy Policy and Cookie Policy I'd like to receive updates and special offers from Dow Jones and affiliates. Email address is not valid. Agree to the policies to sign up. Subscribe Congratulations! You have been subscribed to our daily Barron’s Next newsletter Newsletters will start being sent to you within 48 hours. Review our Privacy Policy and Cookie Policy 
 
 How is it calculated? 
 
 The DJIA is a “price-weighted” index, which means that it is calculated by adding up the 30 companies’ stock prices and then dividing them by a magic number called the Dow Divisor. The divisor is adjusted to account for stock splits, dividends, or spinoffs, which affect the share prices of Dow components. 
 
 Because it is price-weighted, stocks with a higher price carry a greater weight in the index. For example, A 10% change in 3M’s $204 stock will add more points to the Dow than a 10% change in Cisco’s $31 stock. The S&P 500, another widely-followed index, is market-cap weighted, meaning that an equal percentage change in any of its components will have the same effect on the index’s value, regardless of stock price. 
 
 Which specific companies powered the Dow to 22,000? 
 
 In the 107 trading days since the Dow reached 21,000 on March 1, Boeing led the pack, rising 54% and adding 370 points to the index. McDonald’s and UnitedHealth Group followed, adding 189 and 172 points, respectively. IBM was the main drag on the Dow, declining 37.5% since March and costing the index 257 points. 
 
 Why did the Dow just smash through another record? 
 
 Promise of regulatory and tax reform: President Trump and the Republican party have campaigned on business-friendly policies such as a lower corporate tax rate and softer regulations. If successfully implemented, investors believe that corporate earnings will increase. 
 
 Strong economic fundamentals: Low unemployment, slow but steady GDP growth, and other economic indicators point to a still improving economic climate, encouraging optimism which leads to more investment and spending. 
 
 Low interest rates: The Federal Reserve has increased interest rates three times since December, another reason to be optimistic about the economy. Nevertheless, rates are still near historical lows, meaning that investors looking to earn a reasonable return have few options besides the stock market, driving share prices higher. 
 
 Strong corporate earnings: Companies have been earning higher profits and expect to earn more in the future as the economy improves and business and consumer spending increase. 
 
 Weakening dollar: Many of the Dow’s components have large international operations. The U.S. dollar has fallen 10% since the start of the year relative to other currencies, meaning that foreign profits are worth more in dollars and making U.S.-produced goods cheaper and more competitive abroad. 
 
 
 
 
 
 What does Dow 22k mean for me? 
 
 On the surface, not much. The number 22,000 itself is a relatively meaningless milestone and isn’t technically any different than the DJIA hitting 21,756 or 22,011. What’s relevant is the trend, and this year it’s been practically nothing but up. ||||| The latest on developments in financial markets (All times local): 
 
 4:00 p.m. 
 
 The Dow Jones industrial average closed above 22,000 points for the first time, driven by a big gain in Apple on an otherwise mixed day for the market. 
 
 Health care and household goods companies fell Wednesday. Prescription drug distributor Cardinal Health dropped 8.2 percent. 
 
 Movie theater companies plunged after AMC Entertainment gave a weak profit forecast amid a sluggish summer at the box office. AMC slumped 27 percent. 
 
 The Dow Jones industrials rose 52 points, or 0.2 percent, to 22,016. The move was almost entirely due to the jump in Apple's stock. 
 
 The broader Standard & Poor's 500 index edged up 1 point, less than 0.1 percent, to 2,477. The Nasdaq edged down less than a point to 6,362. 
 
 More stocks fell than rose on the New York Stock Exchange. 
 
 ___ 
 
 11:45 a.m. 
 
 A big earnings gain from Apple is sending the Dow Jones industrial average above 22,000 points for the first time, but otherwise stocks are mostly lower. 
 
 Apple soared 5 percent in midday trading Wednesday, accounting for all of the Dow's gain. Apple reported another solid quarter and released a strong forecast late Tuesday. 
 
 Other industries mostly fell, led by drops in health care and household goods companies. Prescription drug distributor Cardinal Health plunged 9.6 percent. 
 
 Movie theater companies fell sharply after AMC Entertainment gave a weak forecast. AMC's stock sank 24 percent. 
 
 The Dow Jones industrials rose 45 points, or 0.2 percent, to 22,010. 
 
 The broader Standard & Poor's 500 index fell 4 points, or 0.2 percent, to 2,472. The Nasdaq composite lost 24 points, or 0.4 percent, to 6,338. 
 
 ___ 
 
 9:35 a.m. 
 
 A big earnings gain from Apple is sending the Dow Jones industrial average above 22,000 points for the first time. 
 
 Apple soared 6 percent in the first few minutes of trading Wednesday, accounting for all of the Dow's gain. Apple reported another strong quarter and released a strong forecast late Tuesday. 
 
 Drugmaker Illumina jumped 12 percent after beating its earnings forecasts and issuing a strong outlook. 
 
 The Dow was up 68 points, or 0.3 percent, to 22,031. 
 
 The Standard & Poor's 500 index rose 2 points, or 0.2 percent, to 2,478. 
 
 The Nasdaq composite increased 25 points, or 0.4 percent, to 6,388. ||||| Yet those concerns have yet to halt the stock market’s seemingly unstoppable advance. Mr. Trump has repeatedly pointed to record highs in the Dow as a validation of his administration, posting on Twitter on Tuesday morning: 
 
 “Stock Market could hit all-time high (again) 22,000 today. Was 18,000 only 6 months ago on Election Day. Mainstream media seldom mentions!” 
 
 And while it is true that there has been little in terms of legislative action to back up his boast, investment experts say that the president’s promise to slash regulations and cut taxes — even if unfulfilled — has stoked long-dormant animal spirits among investors. That corporate earnings are excelling and the global economy is growing faster than many expected has only added to the bullish vibe. 
 
 “Whether you like the administration, the people, the rhetoric or not, there is no overstating just how powerful the animal spirits have been,” said Atul Lele, chief investment officer for Deltec International Group, an investment firm based in Nassau, Bahamas. “You are seeing it in the data and it is evident in the financial markets as well.” 
 
 While there is no doubt that the animal spirits have done their work, just as important to the market’s recent rally has been the significant fall in the dollar — not just against the euro and the yen, but against more volatile currencies like the Mexican peso and the Brazilian real. 
 
 Even the Chinese renminbi, once criticized by Mr. Trump as artificially low, has gained value against the dollar, climbing more than 3 percent for the year. ||||| U.S. large-cap stocks in the Dow Jones Industrials index stretched to another record high on Tuesday, the sixth consecutive gain, despite disappointing auto sales and tepid economic data. The real highlight came after the close, however, with Apple (AAPL) climbing more than 6 percent in post-market trading after reporting better-than-expected revenues and earnings. 
 
 The stock market's performance, and the Dow's approach of the 22,000 level, has attracted the attention of regular investors who are aggressively chasing this market higher. But the risks to this uptrend are also growing more numerous as memories of the last significant sell-off fade (the last 5 percent pullback was more than a year ago) and sentiment glows white hot. 
 
 I can't shake the feeling of foreboding. Because everywhere I look, sharp contrasts are in play. 
 
 For example, the split between the Dow's melt-up and the rollover in U.S. "hard" economic data (chart below), which will eventually affect corporate earnings growth. When that happens, the bulls won't be able to ignore the reality on the ground any longer. 
 
 President Trump is touting the stock market gains since Election Day on Twitter, a sharp reversal of his pre-election warnings of an ugly bubble. Apple's after-hours rise on Tuesday stands in opposition to the weakness other big-cap tech stocks are showing, including Amazon (AMZN) and Google parent Alphabet (GOOGL) -- both of which have slipped below the $1,000-a-share level. 
 
 Right now, with analyst earnings expectations still lofty, Wall Street is comfortably insulated from the disappointments on the ground. That's a sharp contrast to the midyear decline in earnings expectations seen over the past five years, according to Bank of America Merrill Lynch (chart above). The difference this time has been the energy price rebound. 
 
 While oil prices have indeed recovered from their early 2016 lows, the rest of the economy seems to have hit a wall in recent months as expected pro-growth legislation from the Republicans in Congress and the Trump White House has failed to materialize amid intra-party rancor, turmoil and gridlock. 
 
 Personal income growth has stalled, pushing real disposable income down on a monthly basis for the first time since December as the post-election ebullience fades. Manufacturing activity is coming off boil. U.S. auto sales have returned to lows not seen since 2014. And consumer sentiment is in steady decline. 
 
 Perhaps this explains the sharp drop underway in the Dow Jones Transportation index, which is down more than 6 percent from the high set a few weeks ago. Or in key blue-chip stocks like General Electric (GE), which has entered a bear market down nearly 21 percent from its December high (chart below). Or IBM (IBM), Starbucks (SBUX) and Exxon Mobil (XOM). 
 
 In fact, with the S&P 500 flirting with record highs, exactly 100 of its issues are in downtrends and trading below both their 50-day and 200-day moving averages. The percentage trading above their 150-day moving average has fallen to just 71 percent, down from a high of 83.4 percent in March. 
 
 According to SentimenTrader's Jason Goepfert, since 1928 when the Dow Transports and the Dow Industrials diverged to such an extent as now, the Industrials were down 3.2 percent on average six months later, with a maximum risk of a 10.1 percent drop and a maximum upside gain of 5.8 percent. 
 
 There's more. 
 
 According to the latest American Association of Individual Investors survey, folks are holding their lowest cash allocation since 2000 at a time when stocks are near historic levels of overvaluation. The current cyclically adjusted price-earnings ratio is eclipsing the level it held heading into the 1929 market crash. 
 
 And finally, August through September is historically the worst two-month period of the year for stocks. Since 1980, the S&P 500 has fallen 0.1 percent and 0.7 percent, respectively, on average during this time -- the only two months to show an average negative return. 
 
 If the Dow scratches up and over the 22,000 mark, enjoy it while it lasts. ||||| These crawls are part of an effort to archive pages as they are created and archive the pages that they refer to. That way, as the pages that are referenced are changed or taken from the web, a link to the version that was live when the page was written will be preserved.Then the Internet Archive hopes that references to these archived pages will be put in place of a link that would be otherwise be broken, or a companion link to allow people to see what was originally intended by a page's authors.The goal is to fix all broken links on the web . Crawls of supported "No More 404" sites. ||||| CLOSE It took years for the Dow to climb to 19K, but in just months it has soared to 22K and isn't slowing down. USA TODAY 
 
 This file photo taken on December 8, 2016 shows the Wall Street Bull sculpture in the Financial District in New York. (AFP PHOTO / Bryan R. Smith/AFP/Getty Images) (Photo: BRYAN R. SMITH, AFP/Getty Images) 
 
 The Dow hit a fresh milestone Wednesday, cracking the 22,000 barrier for the first time in its 121-year history. 
 
 So-called "Dow 22K" is the latest sign that the stock market's long climb that began in March 2009 and that has gained momentum this year amid a global economic recovery continues to charge ahead. 
 
 The Dow topped 22,000 minutes into the trading session, climbed as high as 22,036.10 before closing up 52 points, or 0.24%, at 22,016.24. The Dow's first-ever close above 22,000 was fueled by a 4.7% advance and record high finish for iPhone maker Apple, which reported strong earnings late Tuesday. 
 
 The latest milestone for the blue-chip stock gauge, which includes iconic U.S. companies such as Boeing, Coca-Cola, McDonald's and Johnson & Johnson, ignited a fresh debate on Wall Street as to whether the stock price run-up has more room to go or if a market peak is nearing. 
 
 The Dow Jones industrial average has gained 11.4% this year. It is up 236% since its bear market low of 6547.05, which means a $10,000 investment would be worth $33,600 now. 
 
 Joe Quinlan, chief market strategist at New York-based U.S. Trust, downplayed the significance of the Dow's latest 1,000-point climb. The reason? It represents just a 4.3% gain since it topped 21,000 on March 1. 
 
 What would worry Quinlan, however, would be if investors on Wall Street and Main Street get overly excited and start to pile into the market and quickly push the Dow up another 3,000 points. 
 
 "Chatter about Dow 25,000 would worry me," he says, calling it "a sign of a market top" and "too much exuberance." 
 
 Related: 
 
 It took the Dow 154 calendar days to climb from 21,000 to 22,000, according to S&P Dow Jones Indices. In contrast, it took the Dow 2,119 days -- or nearly six years -- to jump from 14,000 to 15,000 due to the Dow's more than 50% plunge during the 2007 to 2009 bear market. 
 
 The Dow's advance is being powered by better business conditions, recovering economies and improving corporate profits in the U.S. and overseas. 
 
 Stock market optimists say the Dow's current rally is based on improving sales and revenues for U.S. companies and not irrational exuberance like the dot-com stock hysteria back in 2000. 
 
 "Don't let the milestones cause you to miss the simple underlying story: corporate earnings are at all-time highs. So stocks are at all-time highs," says Donald Luskin, chief investment officer at TrendMacro in Chicago. That's how it is supposed to work, he adds. 
 
 CLOSE Following an announcement about legislation to overhaul the U.S. immigration system, President Donald Trump touted the record high of the Dow Jones Industrial Average, saying "we picked up four trillion dollars in net worth." (Aug. 2) AP 
 
 A weakening dollar against a basket of foreign currencies is also helping boost profits at big U.S. companies like McDonald's and Boeing that do a lot of business abroad. That's because it makes their products more affordable when purchased with stronger currencies. The Federal Reserve's patient approach to raising interest rates -- which are still near historic lows -- is also providing support for stocks. 
 
 Stocks "can work their way higher, maybe much higher" if interest rates stay very low and central banks around the world continue to provide stimulus to markets, adds David Kotok, chief investment officer at Cumberland Advisors, an investment firm based in Sarasota, Fla. 
 
 Milestones are fun to celebrate, but they don't necessarily tell you where the market is headed next, says Lindsey Bell, an investment strategist at CFRA, a market research firm in New York. 
 
 "I don't think it foretells the next leg of the market," says Bell. 
 
 Risks still remain. The Dow, in addition to getting pricey relative to the earnings streams of its 30 components, also faces potential risk from the inability of Washington lawmakers to work together and get things done, Bell says. The delay in getting many of President Trump's economic agenda items passed through Congress could also weigh on stocks, as a lack of tax cuts and infrastructure spending could curtail growth, Bell adds. Potential budgetary gridlock in coming months could also spook investors. 
 
 Critics of the Dow's recent assault of 22,000 note that it is a "price-weighted" index -- which means its up and down moves are driven largely by its most expensive stocks -- which distorts the true health of the index and the broader market. 
 
 For example, Boeing, which is now the Dow's highest-priced name at $237.95 per share, soared nearly 25% in July and had surged more than 14% in the four trading days after its strong earnings report on July 26 -- accounting for a big chunk of the Dow's gains in its final run to 22,000. The shares slipped less than 1% Wednesday. 
 
 "The Dow is a flawed index where price matters and nothing else," says Mark Arbeter, president of Arbeter Investments, a Holland, Pa., firm that analyzes the health of the market by stock chart patterns, trading volume and trendlines. In the past six trading days, the Dow has risen 403 points. Boeing accounted for 43% of that gain. 
 
 "When should an index be dominated by one stock? Never," says Arbeter. 
 
 Investors should also never get overly confident, no matter how strong the stock market is acting, warns U.S. Trust's Quinlan. 
 
 "Investors tend to forget about risk levels as markets hit new highs every session," says Quinlan. 
 
 Read or Share this story: https://usat.ly/2wlFU8a ||||| The Dow Jones industrial average broke above 22,000 on Wednesday, just 107 trading days after hitting 21,000 for the first time. 
 
 The 30-stock index has gained nearly 1,000 points since March 1, when it hit 21,000 on an intraday and closing basis, thanks in large part to a handful of stocks. 
 
 Boeing shares have had the biggest points impact on the price-weighted Dow, contributing 380.29 points since March 1, followed by McDonald's and UnitedHealth Group with 171.14 and 166.35 points, respectively. Caterpillar and 3M rounded out the top five points contributors, adding 99.44 and 91.22 points, respectively, to the Dow since March 1. 
 
 But the Dow could have reached the elusive 22,000 mark well before had it not been for IBM, Goldman Sachs, General Electric, Chevron and ExxonMobil shares. Since March 1, these stocks have contributed the biggest amount of losses to the Dow. 
 
 Below is a chart showing the biggest contributors of point gains, and losses, to the Dow since it first reached 21,000.
– The Dow eclipsed 22,000 for the first time in its 121-year history on Wednesday, helped to the mark soon after the opening bell by a strong earnings report from Apple. The index fell below the mark at points during the day but closed in milestone territory at 22,016, per the AP. (The S&P 500 ticked up incrementally to 2,477 and the Nasdaq ticked down a smidge to 6,362.) The Dow's record has prompted a flood of commentary and factoids. Examples: Biggest gainer: Since March 1, shares of Boeing had contributed 380 points to the Dow as of Wednesday morning, more than any other company and ahead of McDonald's (171), UnitedHealth (166), Caterpillar (99), and 3M (91), per CNBC. The biggest detractor? IBM had the largest loss over the same span, 251 points. Dollar's role: As the Dow has risen, the US dollar has declined, losing about 10% of its value against major world currencies. The New York Times explores how the two are related, as does USA Today, which notes that a weak dollar helps big companies that do business abroad because their products are more affordable in foreign currencies. Trump's start: The Dow's close above 22,000 means that it has risen 20% in the 183 trading days since Election Day, per the Wall Street Journal. For a new president, that's second only to George HW Bush (171 days) and ahead of Barack Obama (537), George W. Bush (1,626), and Bill Clinton (308). Hold the applause: At MarketWatch, Rex Nutting argues that the cheerleading over the Dow's rise is overblown, given that most Americans don't own very many shares. The rise helps the richest Americans, while the young in particular are out of luck. "I bought my first shares for my retirement account back in the 1970s, so I've benefited from the incredible gains since then," he writes. "But my children are buying high, not low." Warning signs: At MoneyWatch, Anthony Mirhaydari is worried about weak economic fundamentals in regard to personal income growth, manufacturing, US auto sales, consumer sentiment, and more. As for this current surge: "Enjoy it while it lasts." Why the rise? President Trump has been touting the surging Dow for a while now, and a post at Barron's suggests he's due some of the credit. He and the GOP "have campaigned on business-friendly policies such as a lower corporate tax rate and softer regulations," writes Nicholas Jasinski. "If successfully implemented, investors believe that corporate earnings will increase." Also at play: low unemployment, low interest rates, and the aforementioned weak dollar.