YAHOO [BRIEFING.COM]: The stock market opened 2009 with strong gains, breaking above key resistance levels despite a lack of news or data to guide trading.

Stocks encountered a bit of selling pressure in the first few minutes of action, but spent the rest of the session trending higher. Each of the major indices finished near session highs.

The gains, like in recent sessions, were broad-based and without concerted leadership, which signals many investors may be ready to scoop up bargains after a dreary 2008.

However, this week’s near-7% advance came amid very low trading volume. Only twice in the past seven sessions has trading volume on the NYSE exceeded 1 billion shares. Such low trading volume suggests a lack of conviction in the broader market.

Nonetheless, more than 90% of stocks in the S&P 500 closed with gains.

Financials lagged for the entire session, but still gained 1.5%.

Wells Fargo (WFC 29.29, -0.19) and Bank of America (BAC 14.33, +0.25) reversed early losses to help pull the sector higher. The firms announced they completed their acquisitions of Wachovia Bank and Merrill Lynch, respectively.

In other corporate news, media companies Viacom (VIA 21.15, +1.03) and Time Warner Cable (TWC 22.21, +0.76) reached a new programming agreement, though specifics have yet to be announced. 

Energy stocks sported some of the biggest gains, closing 4.3% higher after oil prices reversed early losses. Oil futures were down as much as 8%, but closed 3.5% higher near $46.20 per barrel. The gains come on top of the prior session’s 14% advance. Crude gained more than 20% this week.

The rebound in oil prices follows weeks of weakness stemming from concerns regarding economic headwinds.

Such economic weakness was reflected in the worst ISM manufacturing reading since June 1980. The December reading came in at 32.4%. A number below 50% indicates a contraction.

A weak reading was expected, though, so investors were able to look past the dismal reading and send the major indices to their best levels in over a month.

The major indices did encounter some resistance late in the session, but the Dow was still able to close above 9,000, while the Nasdaq finished above 1,630, and the S&P 500 finished above 930.DJ30 +258.30 NASDAQ +55.18 NQ100 +4.3% R2K +1.3% SP400 +2.4% SP500 +28.55 NASDAQ Adv/Vol/Dec 2030/1.46 bln/736 NYSE Adv/Vol/Dec 2590/1.05 bln/512