Herbalife gained after the SEC charged former KPMG partner Scott London and his friend Bryan Shaw for insider trading. In recorded conversations, London told Shaw specific details about earnings announcements for Herbalife and another KPMG client Deckers. And in one call, London referenced rumors that had been spread about Herbalife going private.
Among earnings, Rite Aid surged after the pharmacy chain posted its second consecutive quarterly profit as the company filled more prescriptions and sold more generic drugs.
Pier 1 Imports slid after the furniture retailer posted earnings that were mostly in line with expectations, but handed in a weaker-than-expected outlook.
Banking giants JPMorgan and Wells Fargo are slated to post earnings on Friday. (Vote Now: Will JPMorgan Meet, Beat, Miss?)
On the economic front, weekly jobless claims declined 42,000 to a seasonally adjusted 346,000, according to the Labor Department, after a huge jump in the prior week. Economists polled by Reuters had expected a reading of 365,000.
Import prices fell in March as weak petroleum costs offset a spike in food prices, according to the Labor Department, matching expectations. The tame inflation environment should allow the Federal Reserve to stay on its ultra-easy monetary policy course as it tries to nurse the economy back to health.
On Wednesday, minutes from the Fed's March meeting released suggested some policymakers expect to slow the pace of asset purchases by mid-year and end them later this year. Under its current quantitative easing program, the Fed purchases $85 billion in Treasurys and mortgage-backed securities each month.
Still, the market rally continued despite concerns about when the central bank might start to pull back its stimulus efforts amid the healing U.S. economy.
Treasury prices eased off their highs after the government sold $13 billion in 30-year bonds at a high yield of 2.998 percent. The bid-to-cover ratio, an indicator of demand, was 2.49.