纽约——华尔街周二突破了最新的里程碑，道琼斯工业平均指数首次突破30，000点。

道琼斯指数上涨454.97点，涨幅1.5%，收于30，046.24点。冠状病毒疫苗开发的进展和向当选总统移交权力的消息令投资者深受鼓舞乔·拜登终于开始了。交易员们还欢迎拜登选择广受尊敬的前美联储主席珍妮特·耶伦(Janet Yellen)担任财政部长的消息。

这个里程碑是一个引人注目的心理门槛，这是一个令人鼓舞的信号，表明市场的反弹正在扩大，超出了少数支撑华尔街度过这场流行病的股票。但对大多数投资者的401(k)账户来说，道琼斯指数在30，000点的意义小于大盘指数也处于创纪录高位的事实。

以下是道琼斯指数如何反弹至10，000点的最新倍数，这是自2017年1月以来的首次，以及这对投资者意味着什么。

具体来说，道琼斯指数是多少？

这是对30家公司的衡量，主要是分布在一系列行业的蓝筹股。其中包括苹果和微软等科技明星，以及波音和卡特彼勒等更传统的工业公司。道琼斯的其他巨头包括耐克和华特迪士尼公司

与市场的许多其他指标不同，道琼斯指数最重要的是一只股票的价格有多大，而不是一家公司的总价值有多少。这意味着UnitedHealth Group上涨1%对道琼斯的影响比苹果上涨1%的影响更大，尽管苹果的市值是该保险公司的6倍以上。这是因为联合健康集团的股价为336.01美元，而苹果为115.17美元，原因是其总股票数量较少。

道琼斯30，000指数有多重要？

这只是一个任意的数字，并不意味着情况比道琼斯指数在29，999点时好得多。更有影响力的是，道琼斯指数终于收复了大流行的所有失地，并再次达到新高。自3月23日跌破18600点以来，该指数已上涨61.5%。

在对冠状病毒的恐慌引发市场惊人的抛售之前，道琼斯指数仅用了9个多月就超过了2月份创下的纪录。

道琼斯指数为何如此之高？

道琼斯指数飙升至3万点，得到了美联储(Federal Reserve)和国会的大力推动，美联储将短期利率下调至约为零，并采取其他措施稳定金融市场，国会为经济提供了数万亿美元的财政援助。

自大流行最初的冲击以来，经济有所改善。例如，失业救济金申领人数从3月份的690万下降到上周的74.2万。公司利润没有最初担心的那么多。COVID疫苗可能在年底开始分发的可能性最近给了市场更多乐观的理由。

在个别公司中，苹果公司在道琼斯工业平均指数(Dow)复苏初期做了大量的提振工作，截至8月底，其股价飙升近275美元，至500美元以上。8月28日，苹果公司的股票四对一分割，将苹果公司的股价降至130美元以下，削弱了其对道琼斯的影响，尽管其总市值继续上升。

自那以来，随着对经济复苏的预期增强，霍尼韦尔和卡特彼勒为道琼斯指数提供了最大的提振。

从长期来看，自2017年初道琼斯指数首次突破2万点大关以来，大多数道琼斯公司的利润大幅上升。在美国运通例如，分析师预计，每股收益将从疫情中反弹，明年达到6.69美元，而2016年的经常性收益为6.07美元。

与此同时，今天的投资者更愿意为每1美元的收益支付更高的价格，因为替代方案的吸引力较小。10年期美国国债周二的收益率为0.88%，而2017年1月为2.5%。

这意味着我的401K做得更好了？

可能吧，但不是因为道琼斯指数在30000点。对于大多数401(k)账户而言，更重要的是标准普尔500指数的表现。这是因为与道琼斯相比，有更多的股票基金要么直接模仿标准普尔500指数，要么以该指数为基准。

近4.6万亿美元的投资直接追踪标准普尔500指数，而另外6.65万亿美元的投资则根据该指数的表现进行衡量。这11.24万亿美元的总额大约是315亿美元投资的360倍，这些投资是以道琼斯指数为基准跟踪或衡量其表现的。

周二的反弹也将标准普尔500指数推高至11月16日创下的历史高点之上。

那么，为什么要关注道琼斯呢？

道琼斯指数最终跃升至3万点表明，推动市场的不再仅仅是科技股。

仅五大科技公司——苹果、微软、亚马逊、脸书和谷歌的母公司——就占据了标准普尔500指数近22%的市值。这使得它们的运动在标准普尔500指数上空有着不可思议的影响力。道琼斯指数甚至不包括亚马逊、Facebook或谷歌的母公司。

与11月道琼斯指数相比，大科技在市场复苏早期的主导地位是标准普尔500指数8月份回到大流行前纪录的一个重要原因。最近，随着一两种疫苗可能很快上市的希望越来越大，股市的涨幅开始扩大。

道琼斯指数更倾向于金融和工业类股，这些行业在此前受到疫情冲击后，最近表现优于科技类股。

下一站是道琼斯40，000，对吗？

华尔街的许多策略师乐观地认为，2021年股市可以继续攀升，主要是因为疫苗的前景。但市场在短期内面临大量威胁。其中最主要的是不断恶化的流行病，这迫使世界各国政府对企业实施不同程度的限制。

激烈的党派之争也意味着，与此同时，国会在为经济提供更多财政支持方面几乎没有取得进展。这对健康和经济来说都是一个潜在的寒冬。

因此，如果道琼斯指数再次来回越过30000点的门槛，不要感到惊讶。

EXPLAINER: Why the Dow topped 30,000 for the first time

NEW YORK -- Wall Street busted through its latest milestone Tuesday, when the Dow Jones Industrial Average topped 30,000 for the first time.

The Dow rose 454.97 points, or 1.5%, to close at 30,046.24. Investors were encouraged by progress in the development of coronavirus vaccines and news that the transition of power to President-elect Joe Biden is finally beginning. Traders also welcomed word that Biden has selected Janet Yellen, a widely respected former Federal Reserve chair, as treasury secretary.

The milestone is an attention-grabbing psychological threshold, and it’s an encouraging signal that the market’s rally is broadening beyond the handful of stocks that carried Wall Street through the pandemic. But the Dow at 30,000 means less to most investors’ 401(k) accounts than the fact that broader market indexes are also at record highs.

Here’s a look at how the Dow has rallied to its latest multiple of 10,000, the first time that’s happened since January 2017, and what it means for investors.

WHAT IS THE DOW, EXACTLY?

It’s a measure of 30 companies, mostly blue-chip stocks spread across a range of industries. They include tech stars like Apple and Microsoft, as well as more traditional industrial companies like Boeing and Caterpillar. Other behemoths in the Dow include Nike and The Walt Disney Co.

Unlike many other measures of the market, the most important thing for the Dow is how big a stock’s price is, not how much a company is worth in total. That means a 1% move for UnitedHealth Group has a bigger effect on the Dow than the same movement for Apple, even though Apple is worth more than six times the insurer. That’s because UnitedHealth Group’s stock price is $336.01 versus $115.17 for Apple, due to having a smaller number of total shares.

HOW BIG A DEAL IS DOW 30,000?

It’s just an arbitrary number, and it doesn’t mean things are much better than when the Dow was at 29,999. What’s more impactful is that the Dow has finally clawed back all its losses from the pandemic and is once again reaching new heights. It is up 61.5% since dropping below 18,600 on March 23.

It took just over nine months for the Dow to surpass the record it had set in February, before panic about the coronavirus triggered the market’s breathtaking sell-off.

WHAT GOT THE DOW THIS HIGH?

The Dow’s rocket ride to 30,000 got big boosts from the Federal Reserve, which slashed short-term interest rates back to roughly zero and took other measures to stabilize financial markets, and Congress, which came through with trillions of dollars of financial aid for the economy.

The economy has improved since the pandemic’s initial shock. For instance, claims for unemployment benefits dropped from 6.9 million in March to 742,000 last week. Company profits didn’t tank as much as initially feared. And the possibility that a COVID vaccine could begin distribution by the end of the year has recently given the market more reason to be optimistic.

Among individual companies, Apple did much of the heavy lifting early in the Dow’s recovery after its price soared nearly $275 to above $500 by late August. A four-for-one stock split on Aug. 28 cut Apple’s stock price below $130, diminishing its impact on the Dow, even though its total market value continued to rise.

Since then, Honeywell and Caterpillar have provided the biggest boosts to the Dow as expectations have built for a recovering economy.

Looking over the longer term, profits strengthened sharply for most Dow companies since it first rose above the 20,000 threshold at the start of 2017. At American Express, for example, analysts expect earnings per share to bounce back from the pandemic and tally $6.69 next year, versus $6.07 in recurring earnings in 2016.

At the same time, investors today are more willing to pay higher prices for each $1 of earnings because alternatives are less attractive. The yield on the 10-year Treasury Tuesday was 0.88% compared with 2.5% in January 2017.

SO THIS MEANS MY 401K IS DOING BETTER?

Probably, but not because the Dow is at 30,000. For most 401(k) accounts, what matters much more is how the S&P 500 is performing. That’s because many, many more stock funds either directly mimic the S&P 500 or benchmark themselves against that index than the Dow.

Nearly $4.6 trillion in investments directly track the S&P 500, while another $6.65 trillion measure themselves against the index’s performance. That total of $11.24 trillion is roughly 360 times the $31.5 billion in investments that track or benchmark their performance against the Dow.

Tuesday's rally also pushed the S&P 500 above its record high set on Nov. 16.

WHY PAY ANY ATTENTION TO THE DOW, THEN?

One thing the Dow’s final leap to 30,000 indicates is that it’s no longer just tech stocks driving the market.

Five Big Tech companies — Apple, Microsoft, Amazon, Facebook and Google’s parent company — alone account for nearly 22% of the S&P 500 by market value. That gives their movements incredible sway over the S&P 500. The Dow doesn’t even include Amazon, Facebook or Google’s parent company.

The dominance of Big Tech early in the market’s recovery is a big reason the S&P 500 returned to its pre-pandemic record in August compared to November for the Dow. More recently, with hopes rising that a vaccine or two may be arriving soon, the stock market’s gains have begun to broaden out.

The Dow is more heavily weighted toward stocks in the financial and industrial industries, which have done better than tech recently after earlier getting walloped by the pandemic.

NEXT STOP IS DOW 40,000, RIGHT?

Many strategists along Wall Street are optimistic that stocks can keep climbing in 2021, mainly because of the prospects for a vaccine. But the market is facing plenty of threats in the near term. Chief among them is the worsening pandemic, which is pushing governments around the world to bring back varying degrees of restrictions on businesses.

Bitter partisanship also means Congress is making little to no progress on delivering more financial support for the economy in the meantime. That sets the stage for a potentially bleak winter for both health and the economy.

So don’t be surprised if the Dow crosses back and forth over the 30,000 threshold a few more times.