Stocks rallied higher on Monday after the U.S. Food and Drug Administration (FDA) approved its first COVID-19 vaccine. Both the S&P 500 and Nasdaq soared to record closing highs, while the Dow Jones Industrial Average climbed over 200 points.

Wall Street major averages are coming off of a losing week last week as investors grew concerns that the Federal Reserve will move to taper its monetary stimulus by the end of this year.

Here's how the market settled on Monday:

S&P 500 Index (SPY  ): +0.85% or +37.86 points to 4,479.53

Dow Jones Industrial Average (DIA  ): +0.61% or +215.63 points to 35,335.71

Nasdaq Composite Index (QQQ  ): +1.55% or +227.99 points to 14,942.65

FDA fully approves Pfizer-BioNTech COVID vaccine:

The FDA announced Monday that it has fully approved Pfizer (PFE  )-BioNTech's (BNTX  ) COVID-19 vaccine for prevention of COVID disease in individuals 16 years of age or older, making it the first vaccine approved for public use in the United States.

"The FDA's approval of this vaccine is a milestone as we continue to battle the COVID-19 pandemic. While this and other vaccines have met the FDA's rigorous, scientific standards for emergency use authorization (EUA), as the first FDA-approved COVID-19 vaccine, the public can be very confident that this vaccine meets the high standards for safety, effectiveness, and manufacturing quality the FDA requires of an approved product," said Dr. Janet Woodcock, acting FDA Commissioner, in a press statement. "Today's milestone puts us one step closer to altering the course of this pandemic in the U.S."

The vaccine, marketed as Comirnaty, also continues to be available under EUA, including for individuals aged 12 through 15 years and for the administration of a third booster dose in certain immunocompromised individuals.

IHS Markit U.S. services and manufacturing activity decelerated in August:

Activity for both the U.S. services and manufacturing sectors decelerated in August as the ongoing spread of the Delta variant harmed overall growth for the month.

IHS Markit's flash August services business activity index published Monday declined to 55.2 from 59.9 in July, marking an 8-month low. Still, readings above the neutral level of 50.0 indicate expansion in a sector.

Moreover, the flash August manufacturing purchasing managers' index also fell to 61.2 from 63.4 in July, marking a 4-month low.

"The expansion slowed sharply again in August as the spread of the Delta variant led to a weakening of demand growth, especially for consumer-facing services, and further frustrated firms' efforts to meet existing sales," Chris Williamson, chief business economist at IHS Markit, said in a press statement.

"Not only have supply chain delays hit a new survey record high, but the August survey saw increasing frustrations in relation to hiring," Williamson added. "Jobs growth waned to the lowest since July of last year as the companies either failed to find suitable staff or existing workers switched jobs."

Existing home sales rise for second straight month:

Sales of previously owned homes rose by 2.0% in July, according to the National Association of Realtors' (NAR) monthly report published Monday. That rate followed a 1.6% increase in June and topped consensus economists expectations for a drop of 0.5% for the month.

July's advance brought existing home sales to a seasonally adjusted rate of 5.99 million, or the highest level since March. Moreover, the inventory of unsold homes increased 7.3% to 1.32 million from June to July, equal to 2.6 months of the monthly sales pace.

The median existing-home sales price for July rose at a year-over-year pace of 17.8%.

"Much of the home sales growth is still occurring in the upper-end markets, while the mid- to lower-tier areas aren't seeing as much growth because there are still too few starter homes available," said Lawrence Yun, NAR's chief economist, in a press statement.

Here's how market benchmarks opened to start the week:

S&P 500 Index: +0.43% or +19.22 points to 4,460.89

Dow Jones Industrial Average: +0.49% or +172.05 points to 35,292.13

Nasdaq Composite Index: +0.44% or +65.23 points to 14,782.66