Stock losses firmed on Monday morning, the first trading day of the new quarter, as a selloff in financials and disappointing auto sales dragged on markets.

The S&P 500 was down 0.44%, the Dow Jones Industrial Average dropped 0.35%, and the Nasdaq fell 0.4%. The tech-heavy Nasdaq had traded at all-time intraday highs earlier Monday after closing at records several days last week. 

Financial stocks were among the worst performers on Monday, continuing the correction following their massive rally since November. The sector received a big boost after Donald Trump was elected president in November. Trump had promised to introduce business-friendly reforms, including relaxing Dodd-Frank regulations, introducing changes to the tax code, and backing infrastructure spending. Faith in Trump's ability to execute these promises was somewhat tarnished after his Obamacare repeal and replace bill failed to secure enough support. 

Industry leaders including Wells Fargo (WFC - Get Report) , Bank of America (BAC - Get Report) , Citigroup (C - Get Report) , HSBC (HSBC) , JPMorgan (JPM - Get Report) and Goldman Sachs (GS - Get Report) were all lower on Monday, while the Financial Select Sector SPDR ETF (XLF - Get Report) fell 1.1%. 

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It was a mixed March for automakers. Ford (F - Get Report) reported weaker sales in March vs. last year with overall sales dropping 7.2% to 236,250 vehicles. Analysts anticipated a decline of 5.6%. Sales of its popular F-series increased by 10% to 81,330 units. Ford fell 3%.

General Motors (GM - Get Report) reported a 1.6% sales increase in March but well below estimates of an increase of 9.6%. The stock fell more than 4%

Toyota (TM - Get Report) sales declined by 2.1%, less than an anticipated drop of 2.7%. In the year to date, Toyota sales in the U.S. have fallen 6.4%. Fiat Chrysler (FCAU - Get Report) reported a 5% drop in unit sales over March, more than double the expected decline. Car sales slid 14%, while truck sales increased 6%.

Manufacturing activity in the U.S. slowed in March, though at a slightly slower pace than anticipated. The ISM Manufacturing Index retreated to 57.2 in March from 57.7 in February, though exceeded economists' targets of 57.1. The measure remained above 50, the line separating expansion from contraction. The ISM employment index reached a six-year high in March.

A separate reading on manufacturing activity showed a decrease in March, though the measure remained in expansion territory. The U.S. Markit manufacturing PMI declined to 53.3 in March from 54.2. Growth was at its lowest in six months.

U.S. construction spending increased in February, reversing a drop in January. Spending rose by 0.8% following a 0.4% decline in January. Economists anticipated a slightly stronger reading of 1% growth.

Wall Street entered the second quarter on Monday with stocks at or close to all-time records. Equities have shown remarkable resilience since the U.S. presidential election last November as investors placed bets the Trump administration would introduce business-friendly tax reform and infrastructure spending.

The Dow ended last week a little more than 450 points from its all-time closing high of 21,115.55 set on March 1. The S&P 500 was just 28 points, or a 1.4% increase, from its record close of 2,395.96 set on the same day. The Nasdaq closed Friday just under its record of 5,914, set on March 30.

For the first quarter, the Nasdaq logged the best gains of the three major benchmark indexes with an increase of 10% over the first three months of the year. The S&P 500 closed up nearly 6% for the first quarter, while the Dow rose almost 5%. The Dow's gain is its sixth quarterly increase in a row, the longest stretch since the end of 2006.

"The second quarter isn't likely to repeat the first, but strong economic fundamentals, along with rising corporate earnings, could continue to push markets higher," said Brad McMillan, chief investment officer for Commonwealth Financial Network. "Rising confidence will support valuation levels and also offers a real possibility of upside surprises in the hard economic data, which could translate into even better-than-expected earnings growth."

Crude oil ended the first quarter with losses of 5.8%, even as the commodity settled Friday at its best level in more than three weeks. Oil had a positive week as a reading on domestic inventories showed a smaller-than-expected rise and production disruptions in Libya increased hopes of a hit to global output.

West Texas Intermediate crude oil was down 0.65% to $50.26 a barrel on Monday morning. 

An explosion in St. Petersburg, Russia, has killed at least 10 people and injured many more, according to reports. Russia's TASS news agency reported of an explosion at the Sennava Ploschchad metro station earlier Monday. The explosion comes as Russian President Vladimir Putin visited the region for a meeting with Alexander Lukashenko of Belarus, with TASS reporting that he had been informed of the incident.

Under Armour (UA - Get Report)  fell 1.5% after FBR Capital downgraded its rating to underperform from market perform. Analyst Susan Anderson said recent channel checks had disappointed and that competition is heating up. 

Tesla (TSLA - Get Report) delivered a record 25,000 vehicles in the first quarter, an increase of 69% from a year earlier. The maker of electric cars said Sunday it delivered about 13,450 Model S cars and about 11,550 Model X SUVs. Tesla said another 4,650 vehicles were being transported to customers at the end of the quarter and will be included in second-quarter deliveries. Production in the first quarter totaled a record 25,418 vehicles, Tesla said. Tesla shares rose 4.8%.

FactSet (FDS - Get Report) was slightly higher after raising its profit and sales estimates for its third quarter. The financials database company anticipates quarterly sales between $311 million and $317 million, up from its previous range of $301 million to $307 million. Adjusted earnings are expected to come in between $1.81 to $1.87 a share. The previous range was $1.80 to $1.86. 

Casino owners Wynn Resorts (WYNN - Get Report) and Las Vegas Sands (LVS - Get Report)  moved higher after March figures for gambling revenue in Macau showed a larger increase than anticipated. Revenue in the gambling destination rose by 18% in March, above an estimated range of 12% to 16%. Gambling revenue has risen for eight straight months. 

Caterpillar (CAT - Get Report) will close its Aurora, Ill. plant, laying off around 800 jobs and moving production to its plants in Decatur, Ill. and North Little Rock, Ark. The heavy machinery company plans to shift the production by the end of next year. Around 1,200 non-production jobs will remain in Aurora.