The Dow cracked the 9,000 level last week for the first time since January, propelled by better-than-expected earnings and positive trending economic data. The rally was broad for the second straight week as the three major indices managed stunning gains. The Nasdaq finally snapped an impressive 12-day winning streak on Friday. The tech-heavy index remains up 55% since the March 9 low. For the week ended July 24:

Dow: Up 4% to 9,093.24
S&P: Up 4% to 979.26
Nasdaq: Up 4.2% to 1,965.96

It was another extraordinarily busy week as companies continued to report second-quarter earnings. Though earnings have been stronger than expected, profits have been based on cost-cutting, not revenue growth, and companies are cautioning that the economy remains in a weak state. Compared with a year ago, most earnings were bleak. According to Standard and Poor's, operating income for companies in the S&P that have reported so far was nearly 29% less than last year, and 80% less than in 2007. How much further can companies polish earnings through cost cuts?

Earnings central
There was not much top-line growth to be found amongst the companies that reported this week, with the exception of Apple (NASDAQ:AAPL), which saw its net income jump 15% on a 12% increase in revenue as demand for the company's iPhone outstripped supply.

Caterpillar (NYSE:CAT) reported a whopping 66% plunge in second-quarter earnings. The world's largest construction and mining equipment company raised its full-year earnings forecast on cost-cutting, while lowering its revenue guidance. The key here is that revenues aren't there yet, and CAT doesn't expect demand to resurface before year end.

Ford posted a surprise profit in the second quarter, though only on a gain from debt restructuring.

Food and beverage
McDonald's (NYSE:MCD) earnings slipped 8% as the once recession-immune company felt the costs of more people eating meals at home. Revenue fell 7%, though on a constant currency basis, revenues increased 4%. June same-store sales were worse than anticipated, though still up 2.6%.

Coke (NYSE:KO) clocked better-than-expected second-quarter earnings as demand from China and India buoyed results. The cola king derives 80% of its sales from outside North America, so the stronger dollar led to a 9% revenue decline.

Tech beat
Microsoft (NASDAQ:MSFT) posted its first full-year revenue decline (3%) since the company went public. Earnings declined 29% as demand for PCs waned. Though the company says it's still a tough economic environment, management said that the PC and computer server markets could see growth in 2010.

Amazon (NASDAQ:AMZN) saw revenues increase 14%, but earnings declined on selling lower-margin items and a legal settlement with Toys "R" Us. Also last week, the company announced a deal to acquire online shoe retailer Zappos.

Financials aren't out of the woods yet
American Express posted a 48% drop in net income as chargeoffs mounted and customers pulled in spending. On the plus side, the company saw slowing growth in the level of delinquencies.

Morgan Stanley (NYSE:MS) clocked its third straight quarterly loss that was twice as bad as analysts' expectations. The bank claims it was actually too conservative versus peers Goldman Sachs and JPMorgan. Ahem.

Wells Fargo posted a nice profit that includes its acquisition of Wachovia; however, signs are beginning to surface that Wachovia's bad loans could weigh on Wells. Uncollectable loans rose 45% from the first quarter.

Separately, real estate losses continue to roil the banking sector. Regional banks SunTrust and Key Corp are proof, as both posted losses in the second quarter. 

What's ahead
This week brings round three for second-quarter earnings as we receive reports from Time Warner to MasterCard and Dow Chemical.

Stay tuned!

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Fool contributor Jennifer Schonberger owns shares of Microsoft but does not own shares of any of the other companies mentioned in this article. Apple and are Motley Fool Stock Advisor recommendations. American Express, Coca-Cola, and Microsoft are Motley Fool Inside Value recommendations. Coca-Cola is a Motley Fool Income Investor pick. The Fool owns shares of American Express. The Motley Fool has a disclosure policy.