Wall Street mayhem boosts news nets

The financial market meltdown zapping 401(k) plans has boosted the bottom line for cable news networks. 

On Black Monday, when Dow Jones plunged 504 points, business channel CNBC had its highest viewership since the markets re-opened after the 9/11 terrorist attacks.

The network averaged 488,000 viewers from 5 a.m. and 7 p.m. Monday (the channel typically pulls less than 300,000). On Tuesday, when stocks rebounded slightly, CNBC went even higher, with 523,000 viewers. CNBC averaged 496,000 for Wednesday when the market suffered another steep plunge.

"CNBC has been intensely focused on delivering real-time information on a financial story that is literally playing out minute to minute, and we feel like we are continuing to deliver on our mission to be fast, actionable and unbiased," says CNBC representative Brian Steel. "Every trading floor is tuned in."

From Monday to Wednesday, all the cable news networks were also up significantly from their third-quarter averages.

In total day, Fox News was up 35% (averaging 1.4 million), CNN was up 27% (864,000) and MSNBC was up 31% (590,000). In primetime, Fox News was up 64% (3.4 million), CNN was up 20% (1.5 million) and MSNBC was up 89% (1.5 million).

Note: Those primetime numbers include some ratings-spiking events unrelated to the stock market crisis, such as Sean Hannity interviewing Sarah Palin on Fox News, and MSNBC's newly launched Rachel Maddow Show drawing strong numbers. Ratings for CNBC's fledgling competitor, financial channel Fox Business Network, are not reported by Nielsen.