随着投资者重新评估冠状病毒突发事件可能造成的潜在经济损害，持续一周的股市大幅下跌有可能终结美国创纪录的牛市，下周将迎来其11周年纪念日。
牛市是由乐观情绪推动的一轮价值增长，乐观情绪认为它将持续下去。然而，熊市是指价值在短时间内下跌超过20%。自2009年3月金融危机结束以来，美国股市一直处于牛市。
周四，道琼斯指数遭遇有史以来最大单日跌幅，下跌4.4%，目前比峰值低10%以上。纳斯达克综合指数收盘时也下跌了4.6%，比最高点下跌了10%以上。
德意志银行证券首席经济学家托尔斯滕·斯洛克指出，S&P 500股市在过去六个交易日的下跌是该指数有史以来最快的10%修正。
这种情况——抹去数万亿美元的市场价值——可能会继续下去。周五早盘，道琼斯指数、S&P 500指数和纳斯达克指数均下跌约3%。
“关键问题是投资者不知道这次冲击的持续时间和严重程度，”斯洛克告诉记者新闻周刊，并补充说“全球衰退的风险正在迅速上升。”
“我们需要一个断路器，它可以是关于疫苗的新闻，关于死亡率的好消息，或者是关于病毒在全球范围内传播开始放缓的消息。”
世界卫生组织已经宣布冠状病毒(正式名称为COVID-19)为全球卫生紧急事件。可能很快就会宣布大流行随着病例数量的增加和在世界范围内的传播。
根据一份报告，截至周五上午，已有83，774例确诊病例，其中绝大多数发生在冠状病毒的发源地中国大陆约翰·霍普斯金大学汇编的追踪器。新病例的数量每天都在增加。
这种病毒的致死率约为2%。追踪者估计目前全球死亡人数为2867人，其中超过93%在中国大陆。
欧洲和中东最近的爆发——特别是意大利和伊朗—给市场带来了新的担忧。中国的密集遏制行动正在损害其全球第二大经济体的经济，在其他地方有一些连锁反应。
“病毒正在扰乱供应链，公司要求员工不要旅行，也不要去上班，这降低了经济中的总工作时间，”斯洛克说。
“与此同时，出去吃饭、看电影、参加体育赛事和音乐会的人越来越少。这一切对企业收益和国内生产总值都有负面影响，在现阶段，我们根本不知道这些影响有多大。”
BNY梅隆投资管理公司的首席策略师艾丽西娅·莱文(Alicia Levine)表示，他们的基本情况仍然是中国经济增长受到一两个季度的冲击，然后是“V型”复苏。但她表示，下滑的可能性“越来越大”
在这种情况下，BNY·梅隆大学有25%的概率认为，全球范围内的大流行会严重扰乱贸易、需求和产出。“至少，我们预计今年上半年会受到冲击，”莱文说新闻周刊。
正是在这种不确定的背景下，市场正在下跌。“市场讨厌不确定性，并面临不确定的经济传染影响，”莱文说。
“抛售最终可能打击支撑经济的消费者。为了让新资本发挥作用，投资者需要相信对增长的冲击是暂时的，而且仅限于第一至第二季度。
“市场刚刚开始对全球经济增长产生更大、更广泛的冲击，这种冲击将持续到第一季度之后……经济的不确定性是民主党人争夺2020年总统大选的不稳定因素之一。至少，2020年的收益预期会降低，但下调幅度不确定。
S&P道琼斯指数高级指数分析师霍华德·西尔弗布拉特告诉记者新闻周刊市场主要关注的是冠状病毒对企业收益的影响，随着外出人数减少，企业收益可能会受到消费者支出下降的影响。
Silverblatt说，消费者支出一直支撑着市场，因为“企业支出令人失望”
他还表示，随着中国生产停滞，进口下降引发的供应问题“可能造成短缺，推高价格”。
西尔弗布拉特告诉新闻周刊最初市场下跌是“重新确定了病毒的影响”，尽管他表示，政治和股票估值也存在一些“背景问题”,因为牛市提高了许多公司的市盈率。
“事件将决定我们是否阻止牛市。迄今为止，交易已经下跌，但并非失控，没有恐慌，”西尔弗布拉特说。
AJ贝尔公司的投资总监拉斯·莫尔德指出，S&P 500最近的下跌使其回到了10月份的水平。“把下跌放在那个背景下，这真的没什么大不了的，”莫尔德说新闻周刊。
“真正发生的是，一些泡沫已经被吹走，这个市场已经变成了一个充满泡沫的市场，2020年初，像特斯拉、超越肉类和维珍银河这样相当投机的计数器取得了惊人的收益(甚至比特币也卷土重来)。
“市场已经运行了10年，10%的调整非常罕见——事实上非常罕见。这种波动性的缺失是不正常的，而不是它的突然飙升。”
莫尔德表示，市场“刚刚意识到这一点，尽管病毒是一个大问题，很难量化其影响，而且它正在影响短期经济活动，但抛售恰恰反映了市场的过度繁荣和对风险的麻木不仁。”
他补充道:“有一句老话是这样说的，‘股价上下波动’，这似乎是另一个例子。我们早就应该进行修正了，现在我们有了一个。”
2020年2月28日，纽约市华尔街，交易者在纽约证券交易所的开市钟工作。随着全球市场即将以另一轮暴跌结束自2008年以来最糟糕的一周，华尔街的损失在经历了一轮痛苦的开盘后进一步加深。
CORONAVIRUS SELL-OFF THREATENS TO END U.S. STOCK MARKET'S DECADE-LONG BULL RUN
A week of continued sharp stock market falls is threatening to end America's record bull market, which is set to mark its eleventh anniversary next week, as investors reassess the potential economic damage the coronavirus emergency could cause.
A bull market is a run of value growth fueled by optimism that it will continue. A bear market, however, is when the value drops by more than 20 percent in a short period of time. The current bull market in U.S. stocks has run since March 2009 at the end of the financial crisis.
The Dow Jones suffered the steepest one-day fall in its history on Thursday, down 4.4 percent, and is now more 10 percent below its peak. The Nasdaq Composite also closed down 4.6 percent and is more than 10 percent off its peak.
The S&P 500's decline over the past six trading days is the fastest 10 percent correction from an all-time high the index has ever seen, noted Torsten Slok, chief economist Deutsche Bank Securities.
And that—the wiping off of trillions of dollars of market value—may continue. The Dow, S&P 500, and Nasdaq all slid by around 3 percent in trading early on Friday morning.
"The key issue is that investors don't know the duration and severity of this shock," Slok told Newsweek, adding that the "risk of a global recession is rising quickly."
"We need a circuit breaker, which could be news about a vaccine, better news about mortality rates, or news about the spread of the virus beginning to slow down globally."
The World Health Organization has already declared the coronavirus, known formally as COVID-19, a global health emergency. It may soon be declared a pandemic as case numbers rise and spread across the world.
As of Friday morning, there were 83,774 confirmed cases, the vast majority of which are in mainland China, where the coronavirus originated, according to a tracker compiled by John Hopkins University. The number of new cases grows each day.
The virus has a fatality rate of around 2 percent. The tracker puts the current death toll worldwide at 2,867, more than 93 percent of which are in mainland China.
Recent flare-ups in Europe and the Middle East—particularly Italy and Iran—is giving markets new cause for concern. Intensive containment efforts in China are hurting its economy, the second-largest in the world, with a number of knock-on effects elsewhere.
"The virus is disrupting supply chains, and companies are asking workers not to travel and not to go to work, which is lowering the total amount of hours worked in the economy," Slok said.
"At the same time fewer people go out to eat and to movies and sports events and concerts. This all has a negative impact on corporate earnings and GDP, and we simply don't know at this stage the magnitude of these effects."
Alicia Levine, chief strategist at BNY Mellon Investment Management, said their base case is still a one or two quarter hit to China's economic growth and then a "V-shaped" recovery. But she said the downside scenario is "increasingly more likely."
In this scenario, which BNY Mellon has at a 25 percent probability, there is a global pandemic that significantly disrupts trade, demand, and output. "At minimum, we would expect the hit to be over the first half of the year," Levine told Newsweek.
It is in this uncertain context that markets are falling. "Markets hate uncertainty and are faced with uncertain economic impact of contagion," Levine said.
"The sell-off could ultimately hit the consumer which has been holding up the economy. In order to put fresh capital to work, investors need to believe that the hit to growth is temporary and confined to the first-to-second quarters.
"The markets just began to price in a larger and more widespread hit to global growth which will last well past the first quarter… The economic uncertainty comes on top of the unsettled race between the Democrats for the 2020 presidential race. At minimum, earnings estimates for 2020 will go lower but the magnitude of the cut is uncertain."
Howard Silverblatt, senior index analyst for S&P Dow Jones Indices, told Newsweek that the market's main concern is the impact of the coronavirus on corporate earnings, which are likely to be hit by lower consumer spending as fewer people go out.
Consumer spending has been supporting the market, Silverblatt said, because "corporate spending has been disappointing."
He also said the supply issues stemming from lower imports "could create shortages and push up prices" as Chinese production stalls.
Silverblatt told Newsweek the initial market fall was it "repricing that impact of the virus," though he said there is also some "background concern" about politics and stock valuations, with the bull run increasing the earnings-to-valuation ratio for many companies.
"Events will determine if we stop the bull. To date trading has been down, but not uncontrolled, with no panic," Silverblatt said.
Russ Mould, investment director at AJ Bell, noted that the S&P 500's recent drop has taken it back to where it was in October. "Putting the drop in that context it's really not such a big deal," Mould told Newsweek.
"All that has really happened is that some froth has been blown off what had become a pretty bubbly market, with fairly speculative counters like Tesla, Beyond Meat and Virgin Galactic making spectacular gains in early 2020 (and even Bitcoin making a comeback).
"Markets have been on 10-year run and 10 percent corrections have been very—indeed unusually—rare. It is this absence of volatility that has been abnormal, not the sudden spike in it."
Mould said markets are "just waking up to that and while the virus is a big concern, and it is hard to quantify its impact and it is affecting near-term economic activity the sell-off is just as much a reflection of how (over)exuberant markets had become and insensitive to risk."
He added: "There is an old saying about how 'share prices ride the escalator up and the elevator down' and this looks to be another example of that. We've been overdue a correction and now we have got one."
Traders work during the opening bell at the New York Stock Exchange (NYSE) on February 28, 2020 at Wall Street in New York City. Losses on Wall Street deepened following a bruising open, as global markets were poised to conclude their worst week since 2008 with another rout.
