Stock Slide Leaves Bulls Wondering

Is Wall Street's rally over, or is it just experiencing a temporary interruption? Investors are pondering that question this morning, after another down day that leaves the major averages on track for their biggest weekly drops of 2013. Today's major influences will be a slew of corporate earnings, economic numbers, and any new developments that may emerge in the Boston Marathon bombing investigation.

The Labor Department's weekly look at initial jobless claims is first on the economic calendar this morning at 8:30 a.m. ET. Economists expect to see 350,000 new claims for the week ending April 13, compared to 346,000 the prior week.

Two reports come at 10 a.m. ET, with the Philadelphia Fed issuing its monthly index for April, and the Conference Board out with its March index of leading economic indicators. Consensus forecasts see a reading of 2.5 for the Philly Fed compared to last month's 2.0, while the LEI is expected to register a 0.2 percent increase for March compared with February's 0.5 percent boost.

A busy week for Fed speakers continues today, with Fed governors Sarah Bloom Raskin and Jeremy Stein scheduled to speak at a Ford Foundation event in New York, while Minneapolis Fed President Naryana Kocherlakota and Richmond Fed President Jeffrey Lacker have public appearances as well. CNBC's Steve Liesman will have an exclusive interview with Lacker at 8am ET.

Dow components Verizon (VZ) and UnitedHealth Group (UNH), along with banking powerhouse Morgan Stanley (MS), lead this morning's list of corporate earnings reports. We'll also get quarterly numbers from PepsiCo (PEP), Philip Morris (PM), Freeport-McMoRan (FCX), AutoNation (AN), Fifth Third (FITB), and KeyCorp (KEY), among others. After the closing bell, Dow components Microsoft (MSFT) and IBM (IBM) will issue their reports, as will Google (GOOG), Advanced Micro Devices (AMD), Chipotle Mexican Grill (CMG), and E*Trade Financial (ETFC).

Dow component American Express (AXP) leads our stocks to watch list, as it reports first quarter profit of $1.15 per share, three cents above estimates. Revenue was slightly below estimates, but Amex did allay concerns that the economy might curtail use of its cards.

eBay (EBAY) reported first quarter profit of $0.63 per share, one cent above estimates, with revenues in line with consensus. However, the online auctioneer gave current quarter guidance that fell short of Street estimates, as it lowers expectations for its European business.

Select Comfort (SCSS) reported first quarter earnings of $0.41 per share, missing estimates by two cents, and the mattress maker has also cut its full year earnings outlook. Select Comfort says a change in marketing strategy was ineffective and that it plans to revert to its proven methods of advertising.

SanDisk (SNDK) reported first quarter earnings of $0.84 per share, five cents above estimates, while revenue was slightly above forecasts. The memory chip and disk drive maker also raised revenue forecasts for the year on expectations of higher prices for memory chips used in smartphones and tablet computers.

General Motors (GM) says its new diesel version of its Chevrolet Cruze gets 46 miles per gallon on the highway, outperforming some hybrids in that category.

LinkedIn (LNKD) is unveiling an overhaul to its mobile application today, in an effort to enhance appeal for the increasing number of people using it on smartphones.

Toyota (TM) has been offered $146.5 million in tax breaks by the state of Kentucky to build the Lexus ES at its Georgetown plant, according to Reuters. The automaker will reportedly be unveiling a plan to do just that tomorrow.

LDK Solar (LDK) has reported its seventh consecutive quarterly loss, just a few days of partially defaulting on a bond payment.

MetroPCS (PCS) has received the endorsement of proxy advisory firm ISS for its deal to merge with T-Mobile USA. That comes after another large proxy firm, Glass Lewis, also recommended that shareholders approve the deal.