To say the rating agencies have been busy this week would be an understatement; I usually cover agency moves individually, but given the volume of breaking news this week, I thought a quick overview might be easier for everyone to digest. Bear cut: Unless you've been under a rock, you already know that Bear Stearns saw its credit-rating outlook cut to negative by Standard & Poor's on concerns over declining prices for mortgage-backed securities - a cut would leave it with the worst credit rating of the major Wall Street firms. Company CFO Sam Molinaro, in a conference call that was supposed to assuage investor concern, then decided to offer up his opinion that the current crunch is the worst he's seen in 22 years. Any guesses where Bear's stock went from there? Fitch downgrades $5 billion in subprime RMBS: The downgrades hit 291 classes, while 526 classes with an outstanding balance of $46 billion were affirmed. (You'll have to read through individual press releases to tease out exactly where the downgrades were.) Moody's reassures regarding subprime exposure: While S&P was busy warning on Bear Stearns, Moody's went ahead and released a report detailing the subprime exposure of major US investment banks and institutionally-active commercial banks. Their conclusion? Everything's (pretty much) just fine -- and while it wasn't specifically mentioned, it's clear that Moody's thinks any downgrade of Bear's credit rating would be a knee-jerk reaction. Countrywide affirmed: Moody's also affirmed Countrywide's debt rating, saying Countrywide will "be able to withstand" blows to its financial position due to current market conditions. S&P affirms, downgrades, watches: Standard & Poor's said it took 23 rating actions this week affecting 23 classes of residential mortgage-backed securities (RMBS) transactions backed by subprime, closed-end second-lien, and Alt-A loan collateral originated in 2005 and 2006. The agency upgraded 14 ratings, lowered six ratings, and placed three ratings on CreditWatch negative. S&P drops three, adds two to select servicer list: S&P pushes Litton, American Home, and GE Commercial Finance off of its list of select servicers. HW readers already know why for each one, most likely. Fitch downgrades American Home's servicer rating: AHM goes to 'RPS3-' across numerous servicing categories, and is put on negative watch. Other servicers downgraded, too: Fitch drops WaMu's primary commercial servicer rating, citing high employee turnover. Litton appears likely to be downgraded soon as well, with Fitch placing the C-BASS affiliate on negative ratings watch due to concerns over operational stability.