Generally speaking, the "black swan" event refers to an event that meets the following three characteristics:
First, it was unexpected.
Second, it has a great impact.
Third, although it is unexpected, human nature urges us to make up reasons for it afterwards, which is more or less explainable and predictable.
Extended data:
Famous events
1, European debt crisis
From June 5438 to February 2009, the three major rating companies in the world, Standard & Poor's, Moody's and Fitch, respectively downgraded Greece's sovereign debt, which triggered a series of "butterfly effects":
The credit ratings of PIIGS (Portugal-Portugal, Italy-Italy, Ireland-Ireland, Greece-Greece, Spain-) have all been downgraded. Two years later, the European debt crisis spread to France, Germany and other core European countries, and the government's austerity policy was protested by national demonstrations, and economic and social contradictions broke out in an all-round way.
Among the five European countries in debt crisis, Italy is undoubtedly the most concerned, and its debt is huge, which plays a decisive role in the euro zone. Therefore, when the European debt crisis finally spread to Italy, both overseas markets and A-share markets responded quickly. In the view of fund managers, this undoubtedly greatly increases the uncertainty of A-share rebound and needs to arouse enough vigilance.
2. Everbright Oolong
1 16, August 2065438, at 0: 05 a.m., the Shanghai Composite Index changed to a dead plate, and the index curve rose linearly. In three minutes, the Shanghai Composite Index soared by more than 5%. Because this day is Friday, it is also the delivery date of the stock index futures contract in August. For a time, "good news theory" and "conspiracy theory" spread one after another.
The "good news" has spread to the implementation of the preferred stock policy, the blue chip has implemented T+0, and the stamp duty has been lowered.
Conspiracy to say that there is a lot of money trying to interfere with the settlement price of the delivery date of the futures index, and so on. A few minutes later, some media pointed out that the index change was caused by the oolong finger of Everbright Securities, but the market did not believe that the index continued to rise.
At noon, the director of Everbright Securities claimed that the "Oolong Finger" did not exist, which made the incident more confusing and seriously interfered with the judgment of some people in the market.
When the market opened in the afternoon, Everbright Securities suspended trading. At the same time, it was announced that the self-operated business of the strategic investment department of Everbright Securities had problems when using its independent arbitrage system, and the company was carrying out relevant verification and disposal work. At this point, the abnormal fluctuation of the index was confirmed to be caused by the "Oolong Finger" of Everbright Securities. After investors learned the truth, the popularity dispersed and the index fell step by step. At the close, the Shanghai Composite Index closed down 0.64%.
References:
Black Swan Event _ Baidu Encyclopedia