The Dow logged its first record since January, powered by a surge in Apple’s stock

The Dow Jones Industrial Average just marked its first intraday all-time high since January, the resumption of a record run for the blue-chip index that had taken a nearly eight-month pause.

The Dow DJIA, +0.95%  on Thursday closed at about 26,657, surging past its Jan. 26 intraday record at 26,616.71 and ending the benchmark’s longest record-setting fallow period—164 trading days—since the 288-day stretch between May 2015 to July 2016, according to Dow Jones Market Data.

Both the Dow and the S&P 500 index SPX, +0.78% fell into correction territory, usually defined as a drop of at least 10% from a recent peak, on Feb. 8. But the Dow has struggled mightily to recover as briskly as its broad-market peer amid worries about trade clashes between the U.S. and China.

The S&P 500 last put in a closing record on Aug. 29 and Wall Street investors had wondered when the Dow, weighed by declines in multinational companies—including Apple Inc. AAPL, +0.76% among the more susceptible to trade clashes, given the scope of its business in China—would be able to hit a record of its own.

In fact, it has been shares of Boeing BA, +0.61%   and Apple, which have helped to drive the Dow to new heights since hitting its year-to-date low on March 23. Apple has contributed 364 points to the price-weighted Dow’s return to record form, while shares of UnitedHealth Group Inc. UNH, +0.40%  added 361 points and Boeing Corp.’s stock added more than 300 points over the period.

It is important to note that the Dow is price-weighted rather than market-weighted like the S&P 500 and the Nasdaq. That means the Dow is more influenced by the stock-price move of its constituents than market value. A $1 move in any one of the Dow’s 30 components equates to a swing in the index of about 7 points (rounded). (Also worth noting is that General Electric changed the values used to calculate the Dow but that has resulted in a marginal change of the so-called Dow divisor to 0.147480719 compared with 0.145233969. On top of that, GE was a negligible factor in the Dow’s overall moves given its share price).

Here’s a list of the top 5 Dow contributors since March 23

• Apple—378 points
• UnitedHealth—372 points
• Boeing—316 points

Here’s the top 5 Dow losers over that period

Thursday’s record run also helped to drive the S&P 500 to its own all-time closing high at 2,930, marking its first record since Aug. 29.

Wall Street’s stock-market resurgence has come on signs of improving fundamentals. In the latest economic data, for example, first-time jobless claims fell by 3,000 last week, dropping to their lowest level since November 1969. Separately, the Philadelphia Fed manufacturing index jumped more than expected in September, rising to 22.9 from 11.9 in the previous month.

That has thus far helped the market shake off worries about trade spats. even as President Donald Trump earlier this week reiterated his hard-line stance on China and said the U.S. had “no choice” but to levy another $267 billion in duties on China.

That would come on top of announced tariffs on about $200 billion in Chinese goods announced late Monday. China responded with tariffs of 5% to 10% on $60 billion worth of U.S. products that will take effect Sept. 24, and said it may introduce more measures if the U.S. goes ahead with higher tariffs.

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