Thursday earnings snapshot: Southwest Airlines, McDonald's, GM

More than 50 companies reported their second-quarter profit Thursday, and investors are optimistic. A strong number of companies have come in higher than planned for the quarter so far.

Seventy-two of the 104 companies in the Standard & Poor's 500 that have reported earnings exceeded expectations, says S&P Capital IQ. That means 69% of companies have reported more profit than analysts were expecting, which is slightly better than 66% that typically do.

Upcoming earnings reports are critical as investors need fundamentals to justify the rich prices they're paying for stocks.

The S&P 500 is trading for 17.6 times expected earnings over the next 12 months, well above the 16 P-E that's been the average over the past 15 years.

Still, not every company saw a sunny outcome. Among Thursday highlights:

Airlines boosted by lower fuel costs

United Continental(UAL) - The airline's stock blew an earlier gain to close down 0.7% at $56.67 Thursday. The company reported record net income of $1.2 billion, or $3.14 a share, thanks to lower fuel costs. That's despite slower sales, with total revenue of $9.9 billion, down 4% year-on-year. Read more: United announces $1.2B quarterly profit

Southwest Airlines(LUV) - This low-fare consumer darling gained 3.9% to $36.48 after reporting its ninth straight quarterly profit record. It reported $691 million in earnings, or $1.03 per diluted share versus $1.02 expected by Thomson Reuters, with revenue of $5.11 billion. Read more: Southwest sets 9th straight quarterly profit record

Pharmaceuticals stay steady

Eli Lilly Co. (LLY) - The company, which makes medicines like Cialis, reported lower earnings than a year ago at $600.8 million, That was adjusted to 90 cents per share, above estimates of $0.74, with slightly increased revenue of $4.98 billion. The stock gained 0.4% to close at $86.76.

Bristol Myers Squibb (BMY) - Bristol Myers Squibb, maker of drugs Plavix and Abilify, reported adjusted income of $890 million, or 53 cents per share, versus the 36 cents expected. The stock slid 1.6% to $68.24.

Food and beverage: Treats fail to trade higher

McDonald's (MCD). The fast-food giant's shares fell 0.5% to $97.09 after the company posted revenue down 10% and global "comps," a key restaurant metric, down 0.7%. The company's earnings per share fell 10% to $1.26, narrowly beating Reuters' estimates of $1.24, after getting a new CEO earlier this year. Read more: McDonalds earnings, revenues slide in the second quarter

Dr. Pepper Snapple (DPS). The drink company reported second-quarter profit of $220 million, with earnings of $1.13 per share, vs. the $1.10 expected. The maker of beverages like Schweppes, Hawaiian Punch and YooHoo posted revenue of $1.66 billion. Shares were trading down 1.9% to $77.26.

Dunkin Brands (DNKN). Shares of the coffeehouse and doughnut dealer fell 4.9% to $53.75 despite it reporting profits of $48.5 million, and adjusted earnings of 50 cents per share, and revenue of $211.4 million.

Starbucks (SBUX). On the other hand, frappuccino peddler Starbucks saw shares trading at $58.49, up 3.4% in after-hours trading, after posting net income of $626.7 million, or $0.41 per share, in line with Reuters' estimates. Sales were up a tasty 18% on $4.9 billion in revenue. Read more: Starbucks sales surge 18% in Q3

Industrial & Business suppliers feel pressure from abroad

Caterpillar (CAT). Shares of the multinational equipment manufacturer were down 3.6% to $76.88 after reporting net profit of $710 million in the second quarter, down 28% from the same period a year earlier. Revenue plunged 13% to $12.3 billion due to pressure from foreign economies. Adjusted earnings were $1.27 per share, in line with expectations. Read more: Caterpillar hurt by currency, foreign markets

Dow Chemical (DOW). The maker of plastics and chemicals used in everything from paint, to cleaning products to insulation saw its shares fall 4.5% to $47.76. Although second-quarter profit of 91 cents a share beat estimates, revenue fell 13% to $12.91 billion due to pressure from oil prices and the strong dollar.

3M (MMM). The company, which makes thousands of products ranging from from scotch tape to industrial coatings, earned $1.3 billion, or $2.02 per share, 2 cents above estimates. But revenue dropped to $7.69 billion, and shares were down 3.8% to $149.50.

Consumers buying SUVs, shoes and Internet

General Motors (GM). The automaker's shares gained 4.0% to $31.50 as strong truck sales helped it post net income of $1.1 billion, or $1.29 per share, in the second quarter, beating Reuters estimates of $1.09. The company appears to be rebounding from a wave of recalls due to faulty ignition switches. Read more: GM beats second-quarter forecast on truck, SUV sales

Comcast's (CCV). The cable company said second-quarter net income rose 7.3% to $2.1 billion, with adjusted earnings per share totaled 84 cents, matching Reuters' estimates. Revenue rose 11.3% to $18.7 billion, but the stock fell 0.2% to $25.57. The media and telecom behemoth was boosted by cable content from NBCUniversal and movies from Universal Studios, and is seeing more customers sign up for Internet service, and fewer for TV. Read more: Comcast Q2 income up 7.3% as revenue rises at NBC, cable unit

AT&T (T) also saw a boost from new wireless subscribers. The telecom giant  reported $3 billion of net income, with earnings per diluted share totaled 69 cents, surpassing analysts' consensus estimates of 63 cents, according to FactSet. Consolidated revenues of $33 billion, were up 1.4% from a year ago and shares of AT&T were up more than 2% in after-hours trading to $34.71. Read more: AT&T beats Q2 earnings estimates, adds 2 million wireless subscribers

Under Armour (UA). The athletic apparel company's profit and revenue surpassed Wall Street expectations, after completely selling out line of shoes inspired by NBA champ Stephen Curry, with revenue rising 29%. Net income was 7 cents per share, vs. 5 cents expected by Thomson Reuters. Under Armour posted revenues of $784 million, and net income of $14.8 million. Shares were up 7.3% to $95.93.

Amazon (AMZN) And for everything else you want to buy, there's Amazon.  Shares rose 18% after hours after surprise news that revenue rose 20% to $23.1 billion on a profit of $92 million, or $0.19 a share. Reuters; analysts had expected a 0.14 loss per share. Read more: Amazon shares surge on earnings surprise

Contributing: The Associated Press, Matt Kratz