Stocks rose on Monday, building on last week's strength, as the passage of a bill overhauling the healthcare system ended much of the uncertainty about the issue for investors.

While some analysts raised concerns the bill, approved on Sunday, could squeeze company profits and add to costs, they said much of the negative impact was already priced in.

Whether you like healthcare or not, there's now certainty about what's going to happen, said Matt Kaufler, portfolio manager and equity analyst at Clover Capital Management in Rochester, New York.

If it hadn't passed, the issue would've been how much longer the process was going to continue.

The Dow Jones industrial average <.DJI> was up 43.91 points, or 0.41 percent, at 10,785.89. The Standard & Poor's 500 Index <.SPX> was up 5.91 points, or 0.51 percent, at 1,165.81. The Nasdaq Composite Index <.IXIC> was up 20.99 points, or 0.88 percent, at 2,395.40.

Among drug companies, Pfizer Inc
added 1.4 percent to $17.15 while Merck & Co advanced 0.6 percent to $38.30. Both companies are Dow components.

Insurance companies were mixed, with WellPoint Inc down 1.1 percent to $64.39 and Aetna Inc up 0.5 percent to $34.64. Molina Healthcare , which stands to gain from the extension of Medicaid benefits, rose 3.6 percent to $25.33.

Many insurance providers posted strong gains in the week before the bill was passed. The Morgan Stanley Healthcare Payor Index <.HMO> rose 1.3 percent for a sixth straight session of gains.

After initially trading lower, the Dow rebounded to finish at a 17-month high and its ninth gain in 10 sessions.

The fact that we didn't see a big decline early on helped strengthen some of the confidence in the overall market, said Robert Pavlik, chief market strategist at Banyan Partners in New York.

The average's top boost was Boeing Co , which rose 1.9 percent to $72.04 after Barclays raised its price target on the planemaker.

Big-cap tech companies lifted the Nasdaq to its highest close since August 2008. Oracle Corp advanced 1.8 percent to $25.65. The business software maker is scheduled to report results later this week.

Google Inc edged 0.4 percent lower to $557.95. Earlier it said visitors to its China search engine are being redirected to the Hong Kong-based engine following unsuccessful talks with the Chinese government about operating an uncensored search engine in the country.

U.S.-listed shares of Chinese Internet search firm Baidu Inc rose 1.6 percent to $578.91.

Apple Inc gained 1.2 percent to $224.87.

Jeweler Tiffany & Co reported a fourth-quarter profit that was weaker than expected but gave a full-year profit view that was above consensus. The stock slipped 0.3 percent to $47.41.

CNX Gas Corp shares surged 23 percent to $37.84 a day after its parent company, Consol Energy Inc , reached a deal with T. Rowe Price Associates to tender CNX shares. Under the agreement, Consol will buy the shares for $38.25 per share, compared with the company's Friday closing price of $30.80.

Shares of Consol fell 1.9 percent to $44.69.

About 7.93 billion shares traded on the New York Stock Exchange, the American Stock Exchange and Nasdaq, making it one of the slowest days of the year.

Advancing stocks outnumbered declining ones on the NYSE by a ratio of about 2 to 1. On the Nasdaq, roughly two stocks rose for every one that fell.

(Editing by Kenneth Barry)