From Wikipedia, the free encyclopedia - View original article
|Dow Jones Industrial Average|
|Historical logarithmic graph of the DJIA from 1896 to July 2011.|
|Foundation||DJIA: May 26, 1896|
(DJA: February 16, 1885)
|Operator||S&P Dow Jones Indices|
|Exchanges||New York Stock Exchange|
|Website||Dow Jones Averages|
|Dow Jones Industrial Average|
|Historical logarithmic graph of the DJIA from 1896 to July 2011.|
|Foundation||DJIA: May 26, 1896|
(DJA: February 16, 1885)
|Operator||S&P Dow Jones Indices|
|Exchanges||New York Stock Exchange|
|Website||Dow Jones Averages|
The Dow Jones Industrial Average / /, also called the Industrial Average, the Dow Jones, the Dow Jones Industrial, the Dow 30, or simply the Dow, is a stock market index, and one of several indices created by Wall Street Journal editor and Dow Jones & Company co-founder Charles Dow. The industrial average was first calculated on May 26, 1896. Currently owned by S&P Dow Jones Indices, which is majority owned by McGraw-Hill Financial, it is the most notable of the Dow Averages, of which the first (non-industrial) was first published on February 16, 1885. The averages are named after Dow and one of his business associates, statistician Edward Jones. It is an index that shows how 30 large publicly owned companies based in the United States have traded during a standard trading session in the stock market. It is the second oldest U.S. market index after the Dow Jones Transportation Average, which was also created by Dow.
The Industrial portion of the name is largely historical, as many of the modern 30 components have little or nothing to do with traditional heavy industry. The average is price-weighted, and to compensate for the effects of stock splits and other adjustments, it is currently a scaled average. The value of the Dow is not the actual average of the prices of its component stocks, but rather the sum of the component prices divided by a divisor, which changes whenever one of the component stocks has a stock split or stock dividend, so as to generate a consistent value for the index. Since the divisor is currently less than one, the value of the index is larger than the sum of the component prices. Although the Dow is compiled to gauge the performance of the industrial sector within the American economy, the index's performance continues to be influenced by not only corporate and economic reports, but also by domestic and foreign political events such as war and terrorism, as well as by natural disasters that could potentially lead to economic harm.
Beginning on September 20, 2013, after the close, the Dow Jones Industrial Average consists of the following 30 major American companies:
|3M||NYSE||MMM||Conglomerate||1976-08-09||as Minnesota Mining and Manufacturing|
|American Express||NYSE||AXP||Consumer finance||1982-08-30|
|Boeing||NYSE||BA||Aerospace and defense||1987-03-12|
|Caterpillar||NYSE||CAT||Construction and mining equipment||1991-05-06|
|Chevron||NYSE||CVX||Oil & gas||2008-02-19||also 1930-07-18 to 1999-11-01|
|Cisco Systems||NASDAQ||CSCO||Computer networking||2009-06-08|
|Coca-Cola||NYSE||KO||Beverages||1987-03-12||also 1932-05-26 to 1935-11-20|
|DuPont||NYSE||DD||Chemical industry||1935-11-20||also 1924-01-22 to 1925-08-31|
|ExxonMobil||NYSE||XOM||Oil & gas||1928-10-01||as Standard Oil of New Jersey|
|Goldman Sachs||NYSE||GS||Banking, Financial services||2013-09-20|
|The Home Depot||NYSE||HD||Home improvement retailer||1999-11-01|
|IBM||NYSE||IBM||Computers and technology||1979-06-29||also 1932-05-26 to 1939-03-04|
|Johnson & Johnson||NYSE||JNJ||Pharmaceuticals||1997-03-17|
|Procter & Gamble||NYSE||PG||Consumer goods||1932-05-26|
|UnitedHealth Group||NYSE||UNH||Managed health care||2012-09-24|
|United Technologies||NYSE||UTX||Conglomerate||1939-03-14||as United Aircraft|
|Walt Disney||NYSE||DIS||Broadcasting and entertainment||1991-05-06|
The components of the DJIA have changed 53 times in its 128-year history. General Electric has had the longest continuous presence on the index, with its latest addition being in 1907. More recent changes to the index include the following:
In 1884, Charles Dow composed his first stock average, which contained nine railroads and two industrial companies that appeared in the Customer's Afternoon Letter, a daily two-page financial news bulletin which was the precursor to The Wall Street Journal. On January 2, 1886, the number of stocks represented in what we now call the Dow Jones Transportation Average dropped from 14 to 12, as the Central Pacific Railroad and Central Railroad of New Jersey were dropped from that index. Though comprising the same number of stocks, this index contained only one of the original twelve industrials that would eventually form Dow's most famous index.
Dow calculated his first average purely of industrial stocks on May 26, 1896, creating what is now known as the Dow Jones Industrial Average. Of the original 12 industrials, only General Electric currently remains part of that index. The other 11 were:
When it was first published in the mid-1880s, the index stood at a level of 62.76. It reached a peak of 78.38 during the summer of 1890, but ended up hitting its all-time low of 28.48 in the summer of 1896 during the depths of what later became known as the Panic of 1896. Many of the biggest percentage price moves in the Dow occurred early in its history, as the nascent industrial economy matured. A brief war in 1898 between the United States and the Spanish Empire might have only had a minor impact in the Dow's direction.
The 1900s (decade) would see the Dow halt its momentum as it worked its way through a pair of cataclysmic financial crises; the Panic of 1901 and the Panic of 1907. The Dow would remain stuck in a trading range between 53 and 103 points until late 1914. The negativity surrounding the 1906 San Francisco earthquake did little to improve the economic climate. International disturbances such as the Russo-Japanese War were few and far between and seemed to have little if any influence on the Dow. The average finished the decade at 99.05 points.
At the start of the 1910s, the decade would begin with the Panic of 1910–1911 stifling economic growth for a lengthy period of time. History would later take its course on July 30, 1914; as the average stood at a level of 71.42 when a decision was made to close down the New York Stock Exchange, and suspend trading for a span of four and a half months. Some historians believe the exchange closed because of a concern that markets would plunge as a result of panic over the onset of World War I. An alternative explanation is that the Secretary of the Treasury, William Gibbs McAdoo, closed the exchange because he wanted to conserve the U.S. gold stock in order to launch the Federal Reserve System later that year, with enough gold to keep the United States at par with the gold standard. When the markets reopened on December 12, 1914, the index closed at 74.56, a gain of 4.4 percent. This is frequently reported as a large drop, due to using a later redefinition. Reports from the time say that the day was positive. Following World War I, the United States would experience another downturn in economic activity in what became known as the post-World War I recession. The Dow's performance would remain virtually unchanged from the closing value of the previous decade, adding only 8.26%, from 99.05 points at the beginning of 1910, to a level of 107.23 points at the end of 1919.
During the 1920s, specifically in 1928, the components of the Dow were increased to 30 stocks near the economic height of that decade, which was nicknamed the Roaring Twenties. The prosperous nature of the economic climate, muted the negative influence of an early 1920s recession plus certain international conflicts such as the Polish-Soviet war, the Irish Civil War, the Turkish War of Independence and the initial phase of the Chinese Civil War. The Crash of 1929 in October and the ensuing Great Depression over the next several years returned the average to its starting point, almost 90% below its peak. By July 8, 1932, following its intra-day low of 40.56, the Dow would end up closing the session at 41.22. The high of 381.17 on September 3, 1929, would not be surpassed until 1954, in inflation-adjusted numbers. However, the bottom of the 1929 Crash came just 2½ months later on November 13, 1929, when intra-day it was at the 195.35 level, closing slightly higher at 198.69. For the decade, the Dow would end off with a healthy 131.7% gain, from 107.23 points at the beginning of 1920, to a level of 248.48 points at the end of 1929, just before the bulk of the Crash.
Marked by global instability and the Great Depression, the 1930s contended with several consequential European and Asian outbreaks of war, leading up to catastrophic World War II in 1939. Other conflicts during the decade which affected the stock market included the 1936–1939 Spanish Civil War, the 1935–1936 Second Italo-Abyssinian War, the Soviet-Japanese Border War of 1939 and the Second Sino-Japanese War from 1937. On top of that, the United States dealt with a painful recession in 1937 and 1938 which temporarily brought economic recovery to a halt. The largest one-day percentage gain in the index, 15.34%, happened on March 15, 1933, in the depths of the 1930s bear market when the Dow gained 8.26 points to close at 62.10. However, as a whole throughout the Great Depression, the Dow posted some of its worst performances, for a negative return during most of the 1930s for new and old stock market investors. For the decade, the Dow Jones average was down from 248.48 points at the beginning of 1930, to a stable level of 150.24 points at the end of 1939, a loss of about 40%.
|This section does not cite any references or sources. (May 2014)|
Post-war reconstruction during the 1940s, along with renewed optimism of peace and prosperity, brought about a 39% surge in the Dow from around the 148 level to 206. The strength in the Dow occurred despite a brief recession in 1949 and other global conflicts which started a short time later including the latter stages of the Chinese Civil War, the Greek Civil War, the Indo-Pakistani War of 1947 and the 1948 Arab-Israeli War.
During the 1950s, the Korean War, the Algerian War, the Cold War and other political tensions such as the Cuban Revolution, as well as widespread political and economic changes in Africa during the initial stages of European Decolonization, did not stop the Dow's bullish climb higher. Additionally, the U.S. would also make its way through two grinding recessions; one in 1953 and another in 1958. A 200% increase in the average from a level of 206 to 616 ensued over the course of that decade.
The Dow's bullish behavior began to stall during the 1960s as the U.S. became entangled with foreign political issues. U.S. military excursions included the Bay of Pigs Invasion involving Cuba, the Vietnam War, the Portuguese Colonial War, the Colombian civil war which the U.S. assisted with short-lived counter-guerrilla campaigns, as well as domestic issues such as the Civil Rights Movement and several influential political assassinations. For the decade though, and despite a mild recession between 1960 and 1961, the average still managed a respectable 30% gain from the 616 level to 800.
The 1970s marked a time of economic uncertainty and troubled relations between the U.S. and certain Middle-Eastern countries. To begin with, the decade started off with the ongoing Recession of 1969–70. Following that, the 1970s Energy Crisis ensued which included the 1973–75 recession, the 1973 Oil Crisis as well as the 1979 energy crisis beginning as a prelude to a disastrous economic climate injected with stagflation; the combination between high unemployment and high inflation. However, on November 14, 1972, the average closed above the 1,000 mark (1,003.16) for the first time, during a brief relief rally in the midst of a lengthy bear market. Between January 1973 and December 1974, the average lost 48% of its value in what became known as the 1973–1974 Stock Market Crash; with the situation being exacerbated by the events surrounding the Yom Kippur War. The index closed at 577.60, on December 4, 1974. During 1976, the index went above 1000 several times, and it closed the year at 1,004.75. Although the Vietnam War ended in 1975, new tensions arose towards Iran surrounding the Iranian Revolution in 1979. Other notable disturbances such as the Lebanese Civil War, the Ethiopian Civil War, the Indo-Pakistani War of 1971 and the Angolan Civil War which the U.S. and Soviet Union considered critical to the global balance of power, seemed to have had little influence towards the financial markets. Performance-wise for the decade, gains remained virtually flat, rising less than 5% from about the 800 level to 838.
The 1980s decade started with the early 1980s recession. The index went up in 1980. In early 1981, it broke above 1000 several times, but then went down. The index closed at 776.92, on August 12, 1982, which is below the close of 1965, and is usually considered the start of a secular bull. By October, it went above 1000 again, and closed the year above, permanently. The largest one-day percentage drop occurred on Black Monday; October 19, 1987, when the average fell 22.61%. There were no clear reasons given to explain the crash, but program trading may have been a major contributing factor. On October 13, 1989, the Dow stumbled into another downfall, the 1989 Mini-Crash which initiated the collapse of the junk bond market as the Dow registered a loss of almost 7%.
For the decade, the Dow made a 228% increase from the 838 level to 2,753; despite the market crashes, Silver Thursday, an early 1980s recession, the 1980s oil glut, the Japanese asset price bubble and other political distractions such as the Soviet war in Afghanistan, the Falklands War, the Iran-Iraq War, the Second Sudanese Civil War and the First Intifada in the Middle East. The index had only two negative years, which are 1981 and 1984.
The 1990s brought on rapid advances in technology along with the introduction of the dot-com era. To start off, the markets contended with the 1990 oil price shock compounded with the effects of the Early 1990s recession and a brief European situation surrounding Black Wednesday. Certain influential foreign conflicts such as the 1991 Soviet coup d'état attempt which took place as part of the initial stages of the Dissolution of the USSR and the Fall of Communism; the First and Second Chechen Wars, the Persian Gulf War and the Yugoslav Wars failed to dampen economic enthusiasm surrounding the ongoing Information Age and the "irrational exuberance" (a phrase coined by Alan Greenspan) of the Internet Boom. Even the occurrences of the Rwandan Genocide and the Second Congo War, termed as "Africa's World War" that involved 8 separate African nations which together between the two killed over 5 million people; didn't seem to have any noticeable negative financial impact on the Dow either. Between late 1992 and early 1993, the Dow staggered through the 3,000 level making only modest gains as the Biotechnology sector suffered through the downfall of the Biotech Bubble; as many biotech companies saw their share prices rapidly rise to record levels and then subsequently fall to new all-time lows.
On November 21, 1995, the DJIA closed above the 5,000 level (5,023.55) for the first time. Over the following two years, the Dow would rapidly tower above the 6,000 level during the month of October in 1996, and the 7,000 level in February 1997. On its march higher into record territory, the Dow easily made its way through the 8,000 level in July 1997. However, later in that year during October, the events surrounding the Asian Financial Crisis plunged the Dow into a 554-point loss to a close of 7,161.15; a retrenchment of 7.18% in what became known as the 1997 Mini-Crash. Although internationally there was negativity surrounding the 1998 Russian financial crisis along with the subsequent fallout from the 1998 collapse of the derivatives Long-Term Capital Management hedge fund involving bad bets placed on the movement of the Russian ruble, the Dow would go on to surpass the 9,000 level during the month of April in 1998, making its sentimental push towards the symbolic 10,000 level. On March 29, 1999, the average closed above the 10,000 mark (10,006.78) after flirting with it for two weeks. This prompted a celebration on the trading floor, complete with party hats. The scene at the exchange made front page headlines on many U.S. newspapers such as The New York Times. On May 3, 1999, the Dow achieved its first close above the 11,000 mark (11,014.70). Total gains for the decade exceeded 315%; from the 2,753 level to 11,497.
The Dow averaged a 5.3% return compounded annually for the 20th century, a record Warren Buffett called "a wonderful century"; when he calculated that to achieve that return again, the index would need to close at about 2,000,000 by December 2099. Even during the height of the dot-com era, authors James K. Glassman and Kevin A. Hassett went so far as to publish a book entitled Dow 36,000: The New Strategy for Profiting From the Coming Rise in the Stock Market. Their theory was to imply that stocks were still cheap and it was not too late to benefit from rising prices during the Internet boom.
Characterized by fear on the part of newer investors, the uncertainty of the 2000s (decade) brought on a significant bear market. There was indecision on whether the cyclical bull market represented a prolonged temporary bounce or a new long-term trend. Ultimately, there was widespread resignation and disappointment as the lows were revisited, and in some cases, surpassed near the end of the decade.
The third largest one-day point drop in DJIA history, and largest at the time, occurred on September 17, 2001, the first day of trading after the September 11, 2001 attacks, when the Dow fell 684.81 points, or 7.1%. However, the Dow had been in a downward trend for virtually all of 2001 prior to September 11, losing well over 1000 points between January 2 and September 10, and had lost 187.51 points on September 6, followed by losing 235.4 points on September 7. By the end of that week, the Dow had fallen 1,369.70 points, or 14.3%. However, the Dow began an upward trend shortly after the attacks and quickly regained all lost ground to close above the 10,000 level for the year.
During 2002, the average remained subdued without making substantial gains due to the stock market downturn of 2002 as well as the lingering effects of the dot-com bubble. In 2003, the Dow held steady within the 7,000 to 9,000-point level range by the early 2000s recession, the Afghan War and the Iraq War. But by December of that year, the Dow remarkably returned to the 10,000 mark. In October 2006, four years after its bear market low, the DJIA set fresh record theoretical, intra-day, daily close, weekly, and monthly highs for the first time in almost seven years, closing above the 12,000 level for the first time on the 19th anniversary of Black Monday (1987). On February 27, 2007, the Dow Jones Industrial Average fell 3.3% (415.30 points), its biggest point drop since 2001. The initial drop was caused by a global sell-off after Chinese stocks experienced a mini-crash, yet by April 25, the Dow passed the 13,000 level in trading and closed above that milestone for the first time. On July 19, 2007, the average passed the 14,000 level, completing the fastest 1,000-point advance for the index since 1999. One week later, a 450-point intra-day loss, owing to turbulence in the U.S. sub-prime mortgage market and the soaring value of the yuan, initiated another correction falling below the 13,000 mark, about 10% from its highs.
On October 9, 2007, the Dow Jones Industrial Average closed at a record high of 14,164.53. Two days later on October 11, the Dow traded at an intra-day level high of 14,198.10, a mark which would not be matched until March 2013. In what would normally take many years to accomplish; numerous reasons were cited for the Dow's extremely rapid rise from the 11,000 level in early 2006, to the 14,000 level in late 2007. They included future possible takeovers and mergers, healthy earnings reports particularly in the tech sector, and moderate inflationary numbers; fueling speculation the Federal Reserve would not raise interest rates.
On September 15, 2008, a wider financial crisis became evident when Lehman Brothers filed for Chapter 11 bankruptcy along with the economic effect of record high oil prices which reached almost $150 per barrel two months earlier. On that day, the DJIA lost more than 500 points for only the sixth time in history, returning to its mid-July lows below the 11,000 level. A series of "bailout" packages, including the Emergency Economic Stabilization Act of 2008, proposed and implemented by the Federal Reserve and U.S. Treasury, as well as FDIC-sponsored bank mergers, did not prevent further losses. After nearly six months of extreme volatility during which the Dow experienced its largest one day point loss, largest daily point gain, and largest intra-day range (more than 1,000 points), the index closed at a new twelve-year low of 6,547.05 on March 9, 2009 (after an intra-day low of 6,469.95 during the March 6 session), its lowest close since April 1997, and had lost 20% of its value in only six weeks.
Towards the latter half of 2009, the average rallied towards the 10,000 level amid optimism that the Late-2000s (decade) Recession, the United States Housing Bubble and the Global Financial Crisis of 2008–2009, were easing and possibly coming to an end. For the decade, the Dow saw a rather substantial pullback for a negative return from the 11,497 level to 10,428, a loss of a little over 9%.
During the early part of the 2010s, aided somewhat by the loose monetary policy practiced by the Federal Reserve, the Dow made a notable rally attempt, though with significant volatility due to growing global concerns such as the 2010 European sovereign debt crisis, the Dubai debt crisis, and the United States debt ceiling crisis. On May 6, 2010, the index lost around 400 points over the day, then just after 2:30 pm EDT, it lost about 600 points in just a few minutes, and gained the last amount back about as quickly. The intra-day change at the lowest point was 998.50 points, the largest intra-day point decline ever, representing an intra-day loss of 9.2%. The event, during which the Dow bottomed out at 9,869 before recovering to end with a 3.2% daily loss at 10,520.32, became known as the 2010 Flash Crash. The index closed the half-year at 9,774.02 for a loss of 7.7%.
On May 3, 2013, the Dow surpassed the 15,000 mark for the first time, while later on November 18, it closed above the 16,000 level. Following a strong jobs report on July 3, 2014, the Dow traded above the 17,000 mark for the first time.
Record High Dow Jones Industrial Average Index Values
|Highest Intraday||September 19, 2014||17,350.64|
|Highest Close||September 19, 2014||17,279.74|
The index is tracked by an exchange-traded fund, the SPDR Dow Jones Industrial Average (NYSE Arca: DIA), commonly called "diamonds". This fund is part of the SPDR family of ETFs from State Street Global Advisors. This fund was introduced in 1998, and it was previously called DIAMONDS Trust, Series 1.
Due to the advent of pre-market trading, the "diamonds" provide a very accurate opening value for the average. As an example, if the ETF opens the trading session with a 76¢ loss; then that would strongly indicate roughly a 76-point loss for the Dow within the first few seconds or so, even before all of its components open for trade. Likewise, if the ETF starts the trading session higher by $1.12, then that would signal an approximate gain for the Dow of 112 points at the open, even if some components begin trading at 9:31 am or 9:33 am due to a delay.
Another asset management firm, ProFunds, issue other related DJIA ETFs through ProShares such as the Inverse Performance (NYSE Arca: DOG) for a bearish strategy on the average. That is, when the Dow trades in negative territory, the ETF trades higher; thus, making it not needed to sell short if one has a bearish goal in mind.
ProFunds also issues the 2x (NYSE Arca: DDM), which attempts to match the daily performance of the DJIA by 200% and the Inverse 2x (NYSE Arca: DXD), which attempts to match the inverse daily performance by 200%. In the case of 2x performance, the ETF increases the buying power by leveraging money without using margin. Currently, there are also 3x performance ETFs issued by ProShares that exist too; which attempt to replicate (300% leverage) against the Dow. For 3x performance, the symbol is (NYSE Arca: UDOW), and for Inverse 3x performance, it is (NYSE Arca: SDOW).
In the derivatives market, the CME Group through its subsidiaries the Chicago Mercantile Exchange (CME) and the Chicago Board of Trade (CBOT), issues Futures Contracts; including the E-mini Dow ($5) Futures (YM), the DJIA ($10) Futures (DJ) and the Big Dow DJIA ($25) Futures (DD) which track the average and trade on their exchange floors respectively. Trading is typically carried out in an Open Outcry auction, or over an electronic network such as CME's Globex platform.
The Chicago Board Options Exchange (CBOE) issues Options Contracts on the Dow through the root symbol DJX in combination with long term expiration options called DJX LEAPS. There are also options on the various ETFs, Performance ETFs, Inverse Performance ETFs, 2x Performance ETFs, Inverse 2x Performance ETFs, 3x Performance ETFs, and Inverse 3x Performance ETFs.
To calculate the DJIA, the sum of the prices of all 30 stocks is divided by a divisor, the Dow Divisor. The divisor is adjusted in case of stock splits, spinoffs or similar structural changes, to ensure that such events do not in themselves alter the numerical value of the DJIA. Early on, the initial divisor was composed of the original number of component companies; which made the DJIA at first, a simple arithmetic average. The present divisor, after many adjustments, is less than one (meaning the index is larger than the sum of the prices of the components). That is:
where p are the prices of the component stocks and d is the Dow Divisor.
Events like stock splits or changes in the list of the companies composing the index alter the sum of the component prices. In these cases, in order to avoid discontinuity in the index, the Dow Divisor is updated so that the quotations right before and after the event coincide:
The Dow Divisor is currently 0.15571590501117 as of September 27, 2013. Presently, every $1 change in price in a particular stock within the average, equates to a 6.42 (1/0.15571590501117) point movement.
With the current inclusion of only 30 stocks, critics like Ric Edelman argue that the DJIA is not a very accurate representation of overall market performance. Still, it is the most cited and most widely recognized of the stock market indices. Additionally, the DJIA is criticized for being a price-weighted average, which gives higher-priced stocks more influence over the average than their lower-priced counterparts, but takes no account of the relative industry size or market capitalization of the components. For example, a $1 increase in a lower-priced stock can be negated by a $1 decrease in a much higher-priced stock, even though the lower-priced stock experienced a larger percentage change. In addition, a $1 move in the smallest component of the DJIA has the same effect as a $1 move in the largest component of the average. The Dow would see the negative effects of this price-weighted average during September–October 2008 with a former component AIG. Before its reverse-split adjusted stock price change, the stock collapsed from $22.76 on September 8 to $1.35 on October 27; contributing to a roughly 3,000-point drop in the index. When a stock goes ex-dividend, this is reflected in a loss in the market value of the stock, and thereby in the DJIA.
As of September 2014, IBM and Visa are among the highest priced stocks in the average and therefore have the greatest influence on it. Alternately, Cisco Systems and General Electric are among the lowest priced stocks in the average and have the least amount of sway in the price movement. Many critics of the DJIA recommend the float-adjusted market-value weighted S&P 500 or the Wilshire 5000, the latter of which includes all U.S. equity securities, as better indicators of the U.S. stock market.
A quantitative analysis from 72 years of financial data from the Dow Jones Industrial Average reveals that in times of financial crises, stocks start to move in a more synchronised fashion, increasing the risk of a stock portfolio. The research is published in the journal Scientific Reports. Financial traders try to reduce the inherent risk of holding only one stock by building portfolios, which carry a lower risk, mainly because individual stocks do not tend to experience daily gains and losses in a completely synchronised manner. Tobias Preis, Dror Y. Kenett, H. Eugene Stanley, Dirk Helbing and Eshel Ben-Jacob analyzed daily closing prices of the 30 stocks that form the Dow Jones Industrial Average, from March 1939 to the end of 2010. They found that the average correlation between these stocks increased at the same rate as market stresses. Consequently, the diversification effect, which should protect a portfolio, melts away in times of market losses just when it would be needed most.
|Wikimedia Commons has media related to Dow Jones Industrial Average.|