Red, red, red.

Across the board, companies on Wall St. took a beating Monday as investors reacted to Standard & Poor’s pre-weekend downgrading of the U.S. credit rating from AAA to AA-plus.

It was a manic day of selling, selling and selling some more, as the S&P 500 fell 79.92 points (-6.6 percent), Dow Jones fell 634.76 points (-5.55 percent) and NASDAQ fell 174.72 points (-6.90 percent).

Matching the losses of those stock market heavyweights, new technology-based entrants to the public markets also suffered rapidly declining value in their shares.

Professional social networking service LinkedIn saw the worst losses, dropping $15.89 to $75.47 per share (-17.39 percent). It’s the second dark day of trading in a row for LinkedIn, which on Friday saw its shares dip $4.16 (4.36 percent).

Every other tech company that went public this year saw its shares drop, though none experienced as bad a drop as LinkedIn.

Demand Media, which kicked off the 2011 firestorm of IPOs in January, saw its shares fall a not insignificant $0.90 to $8.36 (-9.72 percent). HomeAway, which raised $216 million in its late June IPO, experienced a $0.57 drop (-1.77 percent) to $31.67 a share. Pandora, one of the first companies to capitalize on the new tech/music wave, experienced a $1.03 loss (-7.62 percent). Finally, Zillow’s shares are down $2.07 to $26.09 (-7.35 percent).  

International companies trading on U.S. exchanges also saw their shares dip. Chinese social networking site Renren shares fell $0.87 (-11.42 percent) and shares in Russian search giant Yandex fell $3.79 (-12.29 percent).

"Markets will rise and fall," said President Barack Obama on Monday, in an attempt to inject some seriously-needed optimism into the economy. "But this is the United States of America. No matter what some agency may say, we have always been and always will be a Triple-A country."

I guess we have a whole week to see if investors agree with that sentiment.