4:10 pm : Stocks ended modestly higher as the S&P 500 climbed 0.2%, and the Dow added 0.4% to register its 19th consecutive Tuesday of gains.

The major averages saw little change during morning action, but afternoon buying interest helped lift the indices to session highs. Most cyclical sectors (with the exception of materials and technology) finished among the leaders, but the defensively-geared health care sector settled atop the leaderboard as biotechnology outperformed.

The iShares Nasdaq Biotechnology ETF (IBB 181.54, +1.78) advanced 1.0%, and prevented the Nasdaq from falling too far behind the other two indices as technology displayed relative weakness.

The technology sector spent the bulk of the day in negative territory as major components failed to partake in the broader market advance. Apple (AAPL 439.66, -3.27) shed 0.7% after the company faced Senate Subcommittee questioning regarding its tax practices while Microsoft (MSFT 34.85, -0.23) lost 0.7% after unveiling its newest gaming console.

Although the majority of the first quarter reporting season is in the rearview mirror, retail earnings continued to trickle in. The SPDR S&P Retail ETF (XRT 78.68, +0.57) settled higher by 0.7% after Saks (SKS 13.67, +1.39) and TJX (TJX 51.73, +0.38) exceeded their top-line estimates while AutoZone (AZO 427.84, +18.79) and Home Depot (HD 78.71, +1.95) beat on earnings and revenue.

Dow component Home Depot climbed to a new record high following its earnings beat, but the report did not help homebuilders as the SPDR S&P Homebuilders

5:58PM NPS Pharm prices 6 mln share public offering of common stock at $14.53 per share (NPSP) 14.53 +0.42 : Co announced the pricing of an underwritten public offering of 6,000,000 shares of its common stock at a price of $14.53 per share to the public. All of the shares are being sold by NPS. The gross proceeds to NPS from this offering are expected to be approximately $87.2 million, before deducting underwriting discounts and commissions, and other estimated offering expenses payable by NPS. The offering is expected to close on or about May 24, 2013, subject to the satisfaction of customary closing conditions. J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC are acting as joint book-running managers for the offering.

5:10PM Nxstage Medical announces new agreements with DaVita (NXTM) 13.51 +0.12 : Co announced that it has entered into new agreements covering its supply of home, critical care and in-center products to DaVita, the kidney care division of DaVita Healthcare Partners Inc. For the use of products for home hemodialysis in the United States, NxStage has executed a second amended and restated National Service Provider Agreement with DaVita (the "Home Agreement"). The Home Agreement continues, in all material respects, the terms of the first amended and restated National Service Provider Agreement between NxStage and DaVita dated July 22, 2010, with pricing for NxStage's products subject to System One home patient growth targets. The term of the Home Agreement extends through December 31, 2015, and thereafter automatically extends on a monthly basis unless terminated by either party. NxStage and DaVita also entered into an agreement covering the purchase of NxStage's System One and other products for acute inpatient therapy within the critical care market through December 31, 2015. Lastly, NxStage's subsidiary, Medisystems, and DaVita extended the term of their Needle Purchase Agreement dated January 6, 2008 through at least December 31, 2014, although DaVita may by October 31, 2013 elect to extend this to December 31, 2015.

5:00PM Merck announces $5 bln accelerated share repurchase (MRK) 47.33 +2.12 : Co, known as MSD outside the United States and Canada, today announced that it has entered into an accelerated share repurchase agreement (ASR) with Goldman, Sachs & Co. to repurchase $5 billion of Merck's common stock. Proceeds from the company's recently concluded debt offering were used to execute the ASR, which is part of Merck's previously announced $15 billion share repurchase program. In the first four months of 2013, Merck repurchased approximately 17.8 million shares for a total of $772 million. As of April 30, 2013, the company's total outstanding share repurchase authorization was $16.1 billion, which included $1.1 billion in authorized repurchases remaining under the program previously announced on April 27, 2011.