The good vibes that carried Wall Street to new records last week lingered on into Monday's session, pushing indexes to close at new highs for their third day in a row.

The Dow Jones Industrial Average gained 0.70% to close at a record 20,412. The S&P 500 finished up 0.52% to close at 2,328. The Nasdaq also added 0.52%, ending the day at 5,763.

The S&P 500 reached $20 trillion in value for the first time on Monday. The best gainers on the Dow were Caterpillar (CAT) - Get Report and JPMorgan Chase (JPM) - Get Report .

Apple (AAPL) - Get Report rode nearly 1% on market momentum to close at a record $133.29 on Monday. The stock was on a tear after UBS analysts noted that its services business was currently undervalued. UBS analyst Steven Milunovich said on Monday that Apple's shares would be at least 10% higher if its services arm was valued like PayPal's businesses. The new record snapped the old one set in February 2015.  

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Wall Street rallied to new heights last week as Donald Trump made vague promises of tax reform, hopes for which had given markets a big boost in the two months after the U.S. election in November. Trump said he would deliver a tax reform plan in the near future.

The president on Thursday, in a meeting with airline and airport executives, said that lowering the overall tax burden on American businesses was important, adding, "We're going to announce something I would say over the next two or three weeks that will be phenomenal in terms of tax."

"The markets have been giving the new president the benefit of the doubt, believing he will make the economy great again," said Paul Nolte, portfolio manager at Kingsview Asset Management. "Of course, any tax plan must make its way through Congress and is not likely to be passed until later in 2017, meaning any benefits are not likely to be seen until 2018 ... Some very high expectations with little certainty of the outcome may make the markets vulnerable to disappointment."

Markets initially rallied following Trump's surprise victory in November as investors hoped for infrastructure spending, tax cuts, and loosened financial regulations. However, the Trump rally hit the skids following his January inauguration as geopolitical uncertainty, particularly in the wake of a controversial and unconstitutional travel ban, made for market waves. The travel ban, which affected seven Muslim-majority nations, was deemed unconstitutional last week by judges in the 9th Circuit.

On Friday, all three major U.S. stock indexes closed at records for their second day in a row. The Nasdaq ended with its fourth straight closing record on Friday.

Canadian Prime Minister Justin Trudeau and President Trump met in Washington on Monday for the first time since Trump took office. In a post-meeting press conference, Trudeau said "Canada and the U.S. will always be each other's most essential partners." Trump also noted that the two countries have "some wonderful ideas on immigration."

Trump-branded products continue to face the brunt of a largely divisive election campaign. Sears (SHLD) and Kmart announced they would drop 31 Trump Home lines due to weak profitability, following in Nordstrom's (JWN) - Get Report footsteps. Nordstrom recently dropped Ivanka Trump's fashion line after a 32% slump in sales in the last fiscal year.

Basic materials stocks were among the best performers on Monday. Chemours (CC) - Get Report led the way after agreeing to split the $335.4 million settlement in personal-injury lawsuits with former parent DuPont (DD) - Get Report . Lawsuits were tied to toxic chemicals in a West Virginian plant. Other materials stocks such as Rio Tinto (RIO) - Get Report and Vale (VALE) - Get Report were also higher.

Verizon (VZ) - Get Report , the largest wireless provider in the U.S., will begin offering plans with unlimited data starting Monday. Other telecoms including Sprint (S) - Get Report had been gaining ground on the competitor with their own unlimited data plans. The stock fell, while AT&T (T) - Get Report , Sprint, and T-Mobile (TMUS) - Get Report also logged losses.

Allergan (AGN) - Get Report rose after agreeing to acquire Zeltiq Aesthetics (ZLTQ) , a company specializing in fat-reduction technology, in a deal worth $2.475 billion. The acquisition is expected to close in the second half of this year. Shares of Zeltiq rose 12.9%.

Allergan is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer and the AAP team buys or sells AGN? Learn more now.

Williams-Sonoma (WSM) - Get Report was downgraded to market perform from outperform at Telsey Advisory. Promotional activity is increasing and it will likely take longer for a turnaround at Pottery Barn, Telsey said.

Teva Pharmaceuticals (TEVA) - Get Report climbed 5% on Monday after reaffirming its fiscal 2017 guidance. The drugmaker anticipates full-year revenue between $23.8 billion and $24.5 billion and adjusted earnings of $4.90 to $5.30 a share.

Crude oil prices returned to session lows on Monday morning despite proof Organization of Petroleum Exporting Countries largely kept to a production cut agreement that went into effect in January. OPEC members and 11 other countries agreed to reduce production by 1.2 million barrels a day in an agreement reached in November. OPEC said Monday that countries reduced their output by 890,000 barrels a day in January, a 74% compliance rate.

West Texas Intermediate crude was down 1.7% to $52.93 a barrel on Monday.

Gold logged its worst daily loss in two-and-a-half weeks as Wall Street money flooded into equities. Safe-haven assets tend to perform poorly when riskier assets such as equities are on the upswing.