Updated from 4:06 p.m. EDTStocks started the week with solid gains Monday, closing near their session highs, as investors ignored the latest earnings-certification static and focused on good news in the home improvement retail sector. The Dow Jones Industrial Average finished with a gain of 212.73 points, or 2.4%, to 8990.79. The Nasdaq rose 33.53 points, or 2.5%, to 1394.54, and the S&P 500 added 21.93 points, or 2.4%, to 950.70. Most sectors were higher, with the exception of biotechs, precious metals and real estate investment trusts. Semiconductors, Internet stocks and computer hardware makers were among the best performing groups. Advancers led decliners 2-1 on the New York Stock Exchange and 3-2 on the Nasdaq. Stocks came into the week with four straight weeks in the green. A catalyst for last week's action was the arrival of the Aug. 14 CEO certification deadline without serious carnage. But that notion was adjusted Monday morning after the Securities and Exchange Commission said several companies' purportedly certified earnings weren't quite up to the standards the agency had hoped for. Twelve companies that filed financial statements have seen them come back unapproved or delayed, among them Dynegy ( DYN), CMS ( CMS), McLeodUSA ( MCLD) and Alaska Air ( ALK). The SEC also said it will delay judgment on financial statements filed by AOL Time Warner ( AOL), Bristol-Myers ( BMY), Cendant ( CD), Mirant ( MIR), Nicor ( GAS) and Reliant Energy ( REI). On top of that, The Wall Street Journal is reporting that AOL is being probed by federal prosecutors and the SEC for possibly using round-trip trades. Those are the simultaneous buy and sell transactions that several energy companies are under investigation for using, allegedly to goose their revenue figures. On a more positive note, Wilkesboro, N.C.-based Lowe's ( LOW) said second-quarter earnings came in at 59 cents a share, 5 cents better than analysts' forecast, on revenue of $7.49 billion. That also topped the consensus. The company also issued third-quarter guidance that was roughly in line with views and a full-year estimate that is slightly above existing forecasts. Shares of Lowe's were up 11% to $41. The company's main competitor, Home Depot ( HD), saw its shares climb 3% to $29.03. Home Depot is scheduled to report its earnings Tuesday. Elsewhere among retailers, Wal-Mart ( WMT) said its August same-store sales are running at the low end of its 4% to 6% growth estimates. Wal-Mart's stock still rose 1.7% to $54.69, and overall, the sector was stronger, as the Dow Jones U.S. Retail Index added 2.7%. Earnings were also on the mind of analysts at UBS Warburg. The brokerage cut its estimate for the S&P 500's operating profit to $49 from $51 and took its 2003 estimate down to $54 from $58.50, citing lowered expectations about the U.S. consumer and the effect of more conservative accounting. The estimates put the index's current price-to-earnings ratio at about 19 based on 2002 earnings and 17 based on 2003. A blowup at a drug company was dragging several pharmaceutical stocks lower. Disappointing clinical results for an anticancer drug made by AstraZeneca ( AZN) were hurting a slew of pharmaceutical companies. For its part, AstraZeneca fell 16%. The drug, Iressa, was tested in combination with chemotherapy and was found to perform no better than chemo alone. Iressa is part of a class of anticancer drugs known as epidermal growth factor inhibitors, and several other companies with similar candidates, including OSI Pharmaceuticals ( OSIP) and ImClone ( IMCL), were hit by the news. OSI plummeted 57%, and ImClone gave up almost 11%. The American Stock Exchange Pharmaceutical Index was higher by 0.8%, but the Amex Biotechnology Index was losing 2%. Treasuries were climbing around 4 p.m. EDT, with the 10-year note up 9/32 to 100 21/32 and yielding 4.291%. The 30-year was rising 17/32 to 104 24/32, yielding 5.057%. Overseas markets were mixed. Europe was stronger, as London's FTSE 100 gained 2.2% to 4427 and Germany's Xetra DAX added 4.2% to 3838. In Asia, Japan's Nikkei fell 1.9% to 9599, and Hong Kong's Hang Seng dropped 0.2% to 10,247.