The Dow Jones Industrial Average's record-breaking seven-day streak came to a quiet end on Thursday as a mix of earnings came in weaker than expected.

The S&P 500 was lower by 0.37%, the Dow fell 0.43%, and the Nasdaq slid 0.31%. The Dow and S&P 500 had closed the previous session at records. 

Earnings continued to come in at a breakneck pace on Thursday. The second-quarter earnings season is now roughly one-fifth complete. The second-quarter blended earnings estimate is down 3.8%, according to Thomson Reuters. Excluding energy, earnings improved to 0.1% growth, a sign the earnings recession is on the mend.

Southwest (LUV - Get Report) reported a disappointing quarter, missing both analysts' profit and sales forecasts. The airline earned an adjusted $1.19 a share in its June-ended quarter, 2 cents shy of estimates, while revenue of $5.38 billion fell short of $5.40 billion expected. Its third-quarter outlook also missed expectations. Southwest shares declined 11%.

Fellow airlines were also lower as Southwest's quarter triggered fears over the industry's health. Delta Air Lines (DAL - Get Report) , Allegiant Travel (ALGT - Get Report) , Spirit (SAVE - Get Report) , JetBlue (JBLU - Get Report) and United Continental (UAL - Get Report) were all lower.

Intel (INTC - Get Report) was also lower after weak quarterly growth in its server CPU segment, which is seen as the long-term solution to counteract weak PC sales. Sales in the segment grew 5% over the quarter, slowing from 9% growth in the first quarter. Overall earnings topped estimates.

Travelers (TRV - Get Report) reported a 20% drop in second-quarter operating earnings as claims spiked on wildfires in Canada and hailstorm damage around the U.S. over the three months to June. Catastrophe losses over the quarter reached $333 million, up from $221 million a year earlier. Operating profit of $2.20 a share fell from $2.52 a year earlier, though exceeded estimates of $2.07.

In better earnings news, General Motors (GM - Get Report) rose after breezing past quarterly estimates. The U.S. automaker reported a 157% jump in net profit in its second quarter as strong truck demand boosted sales. Revenue increased 11% to $42.4 billion. Sales in Europe also improved, leading GM to report its first quarterly profit in the region in five years.

Qualcomm (QCOM - Get Report) surged thanks to unexpected strength in its chips segment over its recent quarter. Mobile chip shipments totalled 201 million over the third quarter, above Qualcomm's target of between 175 million and 195 million. Total revenue rose 4% to $6 billion, above estimates of $5.58 billion.

Biogen (BIIB - Get Report) added more than 6% after reporting a better-than-expected quarterly results. The drugmaker also announced that CEO George Scangos would be stepping down, effective in coming months once a successor is named.

Crude oil prices also pressured markets, falling on fears over ballooning oversupply. U.S. crude inventories are currently at a historically seasonally high 519.5 million barrels, according to the Energy Information Administration, even as weekly inventories decline.

West Texas Intermediate crude oil settled 2.2% lower Thursday at $44.75 a barrel.

"The global crude market could take longer to balance than expected, as key producers around the world maintain drilling and supply disruptions ease," said Joseph K. George, commodity analyst at Schneider Electric.

The European Central Bank opted to leave interest rates unchanged, as expected, following a meeting on Thursday. The central bank expects rates to remain at the current levels or even lower for an "extended period of time." Monthly asset purchases of 80 billion euros will also run until March 2017, though may be extended to continue longer.

Global financial markets have coped with the United Kingdom's decision to exit the European Union with "encouraging resilience," ECB President Mario Draghi said in a press conference after the announcement.

Existing home sales rose 1.1% to a seasonally adjusted annual pace of 5.57 million in June, the strongest level since February 2007, according to the National Association of Realtors. Economists had expected the sale of previously owned dwellings to reach 5.47 million. The housing sector has remained robust with strong demand pushing sales to multi-year highs.

"Following a slew of favorable housing construction activity data earlier this week, this morning's larger-than-expected increase in existing home sales reinforces the thesis that the housing market is one of the key silver linings in an otherwise lackluster economy," said Lindsey Piegza, chief economist at Stifel.