The Dow Jones Industrial Average drew closer to clinching the 20,000 milestone on Tuesday as it traded intraday above its all-time closing high. 

The Dow was up 0.4% and just 30 points away from the psychologically important level. The index's all-time closing high of 19,911 was reached on Dec. 13.

The S&P 500 was up 0.3%. The Nasdaq gained 0.4% and also touched a new intraday high on Tuesday.

The Dow, a blue-chip index which houses 30 of Wall Street's premium stocks, previously hit the 19,000 mark for the first time just a month ago on Nov. 22.

The Dow first hit 100 in early 1906, just over two decades since its first day of trade. It then took more than 60 years to reach its 10,000 milestone, an achievement it made in November 1972. The Dow first hit 10,000 in March 1999.

A move to 20,000 would be worthy of the headlines, though analysts noted that the Dow holds less significance as a barometer of the markets' health than the more diverse S&P 500.

"Dow 20,000 certainly sounds great, but there are a few things one should keep in mind before putting too much emphasis on it," Andrew Adams, market strategist at Raymond James, wrote in a note. "Remember that the DJIA consists of just 30 U.S. stocks, so it is not as representative of the broad market as it used to be, which is why the S&P 500 is more widely used for benchmarking purposes."

Adams also pointed out that each 1,000-point milestone is less monumental as the percentage increase from one to the next becomes smaller. Back in 1999, a 1,000-point move represented 10% of the index. Today, a 1,000-point move is just 5%.

The Dow has moved higher in response to optimism over President-elect Donald Trump's proposed spending plans. Trump's administration, viewed as Wall Street friendly, has already backed deregulation, infrastructure spending and tax cuts.

Uncertainty reigned after separate terror attacks in Berlin, Zurich and Turkey on Monday. News broke late Monday afternoon that a truck had plowed through the crowd at an outdoor Christmas market in Berlin. Twelve are reportedly dead and 48 have been injured, some severely. Police said the event was "probably a terror attack." The attack echoes a similar act of terror in Nice, France, on Bastille Day earlier this year in which a cargo truck plowed into a crowd, killing 86 and injuring more than 400.

Separately, a gunman shot up a mosque in Zurich on Monday, injuring three. Swiss police have reportedly discovered a body in the vicinity believed to be the shooter. The mosque was popular among Somali migrants.

The Russian ambassador to Turkey was shot and killed in Ankara, Turkey, on Monday. Russia has called the assassination an act of terrorism. The two countries have had tenuous relations as the civil war in Syria spilled over into bordering Turkey. Russia backs Syrian President Bashar al-Assad against rebel troops in Syria.

The three separate acts of terror escalated worries over terrorism worldwide, a concern President-elect Donald Trump often flamed during his campaign.

Safe-haven assets, including currencies, were on the move after the series of terror attacks. The Dollar Index, in particular, was on a tear, climbing 0.44% to trade at 103.58. The index was on track to close at its best level in roughly 14 years.

Stock market gains were broad across all sectors with the financials and telecom spaces receiving the biggest boost. Financials stocks including Citigroup (C - Get Report) , Goldman Sachs (GS - Get Report) , and Bank of America (BAC - Get Report) moved higher, while the Financial Select Sector SPDR ETF (XLF - Get Report) added 0.9%. 

Citigroup is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells C? Learn more now.

BlackBerry (BBRY)  led the telecommunications sector higher after posting surprise profit, a sign its turnaround plans have begun to gain traction. The company earned an adjusted 2 cents a share, higher than consensus of breakeven earnings. Revenue of $289 million fell short of estimates of $330 million. Others in the space moved higher, including AT&T (T - Get Report) , Verizon (VZ - Get Report) , and Telefonica (TEF - Get Report) . 

It's an empty day for economic data, though the calendar should heat up in the back half of the week. There will be a number of data points for investors to trade on including existing home sales on Wednesday, the third and final estimate of third-quarter gross domestic product, and durable goods orders on Thursday, and new home sales data on Friday. This is the final full week of trading of the year.

Rite Aid (RAD - Get Report) jumped 6% after agreeing to sell 865 of its stores to Fred's (FRED - Get Report) for $950 million. The move is part of Rite Aid and Walgreens Boots Alliance (WBA - Get Report) plans to sell off assets in order to gain approval from the Federal Trade Commission for its merger. Fred's shares surged 60%. 

Walgreens is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells WBA? Learn more now.

General Mills (GIS - Get Report) reported second-quarter adjusted earnings of 85 cents a share, missing Wall Street estimates by a penny. Net sales in the quarter fell 7% to $4.1 billion because of lower organic net sales and the divestiture of the North American Green Giant business, the company said.

Darden Restaurants (DRI - Get Report) reported a surge in second-quarter profit. Earnings nearly doubled to 64 cents a share over the quarter, coming in as analysts' expected. Revenue of $1.64 billion came in slightly short of estimates, while same-store sales rose 1.7%, 200 basis points above forecasts. Same-store sales at Olive Garden rose 2.1%.

Salesforce (CRM - Get Report) was initiated with a buy rating and $100 price target at Drexel Hamilton. The company is leveraged to continued migration forward cloud computing, Hamilton said.

Square (SQ - Get Report) was initiated with a buy rating and $18 price target at Nomura. The firm said the company can gain market share and double its gross payment volume by 2020.