UnitedHealth, Delta Air Lines, Inc., Fastenal Co are the ones to read about today.

Leading equity indices in the US declined as Dow Jones was down 0.42% before closing the session at 33,900. After dropping 0.35%, Nasdaq closed at 12,123.

What is an earnings report?

An earnings report is an official statement of a company's profitability over a certain period of time. These reports are typically announced once a quarter, and their timing is considered when making predictions about the market due to the large impact they have on it.

Markets were down, stocks have released their quarterly earnings reports. Have a look at this rundown.

UnitedHealth: EPS of zero, Revenue of $91.93 billion

Following the release of quarterly results, UnitedHealth trades at $511.79.

After ending Thursday at $526.23, UnitedHealth declined to $508.5 Friday before closing at $511.79, thereby losing 2.74% in total.

The past 3 months have been positive for the healthcare solutions and services company as it added 5.35% compared to its 3-month low of $452.06. So far this year, it has been doing worse than the Dow Jones by 3.48%. The healthcare services provider's market cap currently stands at $477.42 billion with an average daily trading volume of 3.46 million shares.

Delta Air Lines: EPS of zero, Revenue of $12.76 billion

Delta Air Lines trades at $33.77 after the company released its quarterly results.

Delta Air Lines spiked to $34 Friday and consolidated before initiating a fresh rally to $33.77. This comes following Thursday's session in which it closed at $33.37. Daily trading volume (14.85 million shares) was slightly above the current multiday average of 11.75 million.

Fastenal: EPS of zero, Revenue of $1.86 billion

Following the release of quarterly results, Fastenal trades at $53.27.

The industrial and construction supplies company went up to $53.27, gaining 1.78%.

This year has been a bright one for the industrial and construction supplies company after trading as low as $43.87 and going on to appreciate by 12.63% year to date. So far this year, it has been under-performing the Nasdaq by 1.64%. Currently, the industrial and construction supplies company has a market capitalization of $30.42 billion with an average daily volume of 3.57 million shares.

Carmax: EPS of zero, Revenue of $5.72 billion

Carmax trades at $69.46 after the company released its quarterly results.

After closing at $69 on Thursday, Carmax maintained a strong bullish bias that helped the stock close higher at $69.46 Friday. However, market bears ensured the the used car company topped out at $71.5 and that by the end of the session, the market had marked out a distinct $68.49 to $71.5 range.

Having soared to a high of $104.22 approximately 7 months ago, the used car company is now trading 33.78% lower. So far this year, it has been outperforming the S&P by 7.09%. Carmax has a market cap of $10.98 billion with an average daily volume of 3.14 million shares.