Investors Follow May Cliche With First-Day Selloff

The old "sell in May and go away" maxim may eventually wind up not applying, but May's first trading day did follow that particular script, with the major averages seeing their biggest one-day drop in two weeks. The Dow, the S&P 500, and the Nasdaq haven't registered May gains since 2009.

The European Central Bank will garner some early morning attention, with its latest policy statement due at 7:45 a.m. ET. The bank is expected to cut its benchmark lending rate by a quarter point to 0.50 percent, the first cut in ten months.

Here in the U.S., investors will see three economic reports at 8:30 a.m. ET, the weekly jobless claims numbers, the March international trade report, and first quarter productivity figures. Economists expect claims to rise to 349,000 for the week ending April 27 from 339,000 the prior week, while the trade deficit is seen coming in at $42.1 billion, down from $43.0 billion in February. Consensus forecasts call for productivity to increase at an annual rate of 1.3 percent for the first quarter, compared to a 1.9 percent drop in 2012's fourth quarter.

The EIA will issue its weekly report on natural gas inventories at 10:30 a.m. ET.

Kellogg (K) and International Paper (IP) are among the well-known companies set to issue quarterly earnings this morning. Also on the morning docket – Becton Dickinson (BDX), Beam (BEAM), Cardinal Health (CAH), Cigna (CI), Estee Lauder (EL), and Marsh & McLennan (MMC).

Kraft Foods (KRFT) will be out with its quarterly numbers after today's closing bell, accompanied by Mylan (MYL), Gilead Sciences (GILD), Dun & Bradstreet (DNB), and AIG (AIG), among others.

Facebook (FB) leads our list of stocks to watch, reporting first quarter profit of $0.12 per share, excluding certain items. That was one cent below Street estimates, though revenues were slightly above consensus as Facebook's mobile advertising sales continued to grow.

Visa (V) earned $1.92 per share for its fiscal second quarter, 11 cents above estimates, with revenues beating forecasts as well. The credit card payment network also raised its earnings forecast for the fiscal year, as credit card use increases.

CBS (CBS) reported first quarter earnings of $0.73 per share, beating analyst estimates by five cents. Revenues were slightly above consensus as well, helped by record ad rates during its broadcast of this year's Super Bowl game.

Yelp (YELP) lost $0.08 per share for the first quarter, three cents wider than analyst were anticipating. However, revenue exceeded consensus, and its second quarter revenue projection is well above Street forecasts. The consumer review site is being helped by strong results in its local and mobile ad segments.

Boston Beer (SAM) fell short of forecasts by 11 cents in reporting first quarter profit of $0.51 per share, though revenues did exceed analyst forecasts. The beer brewer was impacted by higher processing and ingredient costs.

Marriott (MAR) reported first quarter earnings of $0.43 per share, three cents above estimates, with revenues also scoring a beat. The hotel operator saw higher REVPAR (revenue per available room) as well as higher average daily rates.

Avis Budget (CAR) earned $0.08 per share for the first quarter, excluding certain items, beating analyst estimates by six cents. Revenue was essentially in line, and the car rental company raised its full year forecast, thanks in large part to higher rental rates in North America.

Tesoro (TSO) reported first quarter profit of $0.73 per share, three cents above estimates, as the energy producer saw higher fuel sales and increased profit margins in its refining business.

Seagate Technology (STX) reported fiscal third quarter profit of $1.26 per share, excluding certain items, nine cents above estimates, with revenues also beating forecasts. The hard disk drive maker also gave an upbeat revenue forecast for the current quarter.

Moody's (MCO) still has Warren Buffett's Berkshire Hathaway as its largest shareholder, but that stake is now a bit smaller with Berkshire selling 1.75 million shares, according to an SEC filing. Berkshire still holds 12 percent of the rating agency.