(Bloomberg News) Shareholders in U.S.-listed companies can thank Standard & Poor's for making them $1 trillion poorer after the rating firm earlier this month lowered the grade on Treasury securities for the first time to AA+ from AAA. Now, some of the most experienced investors say the stock market losses make no sense.

While the benchmark index for U.S. equities dropped as much as 6.7 percent, or $1.03 trillion, since the Aug. 5 downgrade, 10-year Treasuries rallied the most in 28 months and the government was able to finance its quarterly debt obligations at the lowest interest rates ever. The S&P 500 fell to 12.2 times earnings the first day after the downgrade, the lowest since March 2009, while Treasuries have returned 2 percent since.

"One of the most perverse things I've seen in 25 years of doing this is that S&P downgrades the United States government, and investors' reaction is to run towards the securities that they downgrade, selling businesses without asking at what price," Kevin Rendino, a money manager at BlackRock Inc., which oversees $3.65 trillion in New York, said in an Aug. 23 telephone interview. "Equity prices have swung well too far."

For Rendino and Liz Ann Sonders of Charles Schwab Corp., selling that may have been justified turned indiscriminate following the reduction, creating bargains in equities. The Chicago Board Options Exchange Volatility Index jumped 50 percent to 48, the highest level in 29 months and the biggest jump in more than four years, the first trading day after the action was announced.

Edward Sweeney, a spokesman for S&P, declined to comment on whether the rating company's decision influenced investors' decisions to sell stocks.

Distracted Investors

The downgrade, which conflicted with Moody's Investors Service and Fitch Ratings, turned investors' focus from the 10th straight quarter in which S&P 500 companies topped analyst earnings forecasts. As of Aug. 8, per-share profits had increased 18 percent among companies in the index, with 76 percent topping the average analyst projection, according to data compiled by Bloomberg. Sales rose 13 percent.

The new rating from S&P, which cited "uncertainty" in the policymaking process, is the second-highest and puts the U.S. on the same level as Belgium and New Zealand, above Japan and China. Congressional Republicans warned in November, when outstanding U.S. debt totaled $13.7 trillion, that they would oppose raising the ceiling. Lawmakers agreed on Aug. 2 to boost the limit and adopt a plan to enforce $2.4 trillion in spending reductions over the next 10 years.

'Damage to Confidence'

"It did a lot of damage to confidence, which had been shaky anyway," Sonders, New York-based chief investment strategist at Charles Schwab, said in an Aug. 23 phone interview. Her firm has $1.65 trillion in client assets. "We had started to get a sense of a little bit of a lift for the economy in the second half of the year, and you just kind of wiped it out because of the lack of confidence in our political leaders. S&P reflected that with the downgrade, but what it ended up causing was a real confidence crisis, more than an economic crisis."

Demand for Treasuries surged since the downgrade, helping send the yield on the 10-year note, the benchmark for home mortgages and car loans, to a record low 1.97 percent on Aug. 18. The bonds have returned 3.1 percent this month, poised for the biggest return since December 2008, according to Bank of America Merrill Lynch index data through Aug. 23.

The Treasury sold $35 billion of two-year notes on Aug. 23 at a record low yield of 0.22 percent as investors continued to seek the world's safest securities as refuge from financial market turmoil and a slowing economy. It was the first of that maturity to be sold after the downgrade.

Dollar Gains

The Dollar Index, which IntercontinentalExchange Inc. uses to track the world's reserve currency against six major trade partners, gained 0.3 percent on Aug. 8. The dollar has gained 0.6 percent this month, the sixth-biggest advance among 10 developed-nation currencies, according to Bloomberg Correlation- Weighted Currency Indexes through Aug. 23. The biggest gainer is the franc, up 3.9 percent.

S&P, a New York-based unit of McGraw-Hill Cos., erred when it lowered the ranking and the U.S. merits a "quadruple A," Warren Buffett, the chief executive officer of Omaha, Nebraska- based Berkshire Hathaway Inc. said in an Aug. 6 interview. Berkshire Hathaway made its biggest bets on the stock market on Aug. 8, the day the downgrade sent the S&P 500 to its worst plunge in more than two years, Buffett said in a television interview with Charlie Rose broadcast Aug. 15 on PBS.

'Very Strong'

Under S&P's definitions, debt rated AA is barely different from AAA securities and shows that a borrower's ability to "meet its financial commitment on the obligation is very strong."

Stocks were falling before S&P took action as record interest rates in Spain and Portugal spurred the European Central Bank to resume bond purchases and Congress debated the U.S. debt ceiling, said Warren Koontz of Loomis Sayles & Co. in Boston. The S&P 500 slumped 4.8 percent on Aug. 4, its biggest retreat since 2009, and had lost 11 percent since July 22 as reports showed the world's largest economy grew 0.4 percent in the first quarter and 1.3 percent in the second.

"The downgrade wasn't good, but more important for the selloff was the concern about Washington gridlock over the debt ceiling and the slowdown in Europe," Koontz, who helps manage about $160 billion as head of U.S. large-cap value stocks at Loomis Sayles, said in an Aug. 23 telephone interview. "If we hadn't been in an economic soft patch and if we hadn't had the debt-ceiling ruckus, then we might not have had the downgrade, so I don't think the timing was a surprise."

Worse Than Market

McGraw-Hill declined 15 percent in the two trading sessions following the downgrade, more than twice the S&P 500's loss in the same period.

S&P said on Aug. 22 that it will replace President Deven Sharma with Citibank NA Chief Operating Officer Douglas Peterson at the end of the year as the ratings company faces regulatory scrutiny. The U.S. Senate Banking Committee is looking into the downgrade decision, a committee aide briefed on the matter said Aug. 8. The Securities and Exchange Commission is also scrutinizing the method S&P used and whether the firm protected the confidential decision, a person with direct knowledge of the matter said Aug. 15.

"The fact that S&P's president is stepping down is interesting timing," Quincy Krosby, a market strategist for Newark, New Jersey-based Prudential Financial Inc., said in an Aug. 23 telephone interview. Her firm manages $883 billion. "It begs the question whether S&P thought that everything was fine with this downgrade, its timing and its consequences."

'No Connection'

"There's no connection between the downgrade of the U.S. and Mr. Sharma's departure," S&P's Sweeney said in a phone interview.

Peterson became head of Citigroup's Japan operations in May 2004, a role he kept until January 2010. In November 2004, he became the first foreigner to testify before a Japanese parliamentary committee after regulators found Citigroup's local private bank failed to conduct proper money-laundering checks.

"My mandate is to fix problems," Peterson said during 90 minutes of questioning by lawmakers from governing and opposition parties in the upper house. The probe forced Citigroup to close the private bank and send then-Chief Executive Officer Chuck Prince to Tokyo, where he apologized to regulators and bowed in a gesture of remorse.

Most Since 2008

The S&P 500's 6.7 percent drop on Aug. 8 was the biggest daily decline since December 2008, the height of the financial crisis spurred by Lehman Brothers Holdings Inc.'s bankruptcy. The index has lost 12 percent since July 22, as the debate about extending the debt-ceiling spurred concern the U.S. government would default. It alternated between gains of losses of more than 4.4 percent in the four days after the downgrade, the first time that's ever happened.

Shares of financial firms and banks led declines since the downgrade, losing 5.5 percent as a group. Energy companies and technology stocks have lost more than 3.2 percent. The S&P 500 Aerospace & Defense Index, made up of companies from Northrop Grumman Corp. to Lockheed Martin Corp. that depend on U.S. government spending for revenue, has declined 3.2 percent in the same period.

Northrop, the third-largest U.S. defense contractor, fell 5 percent even after saying second-quarter earnings exceeded analyst projections on July 27. While the shares are beating the S&P 500 by 2.2 percentage point so far this week, companies that don't rely on the government for a significant portion of revenue, such as Host Hotels & Resorts Inc. and Monster Worldwide Inc., have also declined.

Host Hotels

Host Hotels, which owns Ritz-Carltons in San Francisco and Phoenix, posted second-quarter funds from operations that beat the average analyst forecast by 3.1 percent on July 20, boosting the shares 2.6 percent that day. After the U.S. was downgraded, even a projection for the best earnings growth in six years couldn't keep the stock up. It has fallen 19 percent, the sixth- biggest loss in the S&P 500.

The plunge in U.S. stocks that began July 22 pushed valuations down as much as 27 percent by Aug. 8. That was the fastest drop in the price-earnings ratio in 18 months, data compiled by Bloomberg show. The benchmark index traded at 12.2 times reported earnings on Aug. 8., the lowest since the bull market began in March 2009, and it has been hovering around that level since then, as investor fear failed to subside wholly.

'Very Attractive'

"It's definitely appropriate to be worried, and it's normal for people to think about the closest precedent, which is the 2008 credit crisis in the U.S.," Chris Hyzy, the New York- based chief investment officer at U.S. Trust, which oversees about $360 billion, said in an Aug. 23 telephone interview. "However, there are vast differences between that time period and what is occurring around the world now, and therefore the markets have corrected too far, making these current levels very attractive."

Investors sold stocks in August and October 1995 on concern that budget negotiations would fail between President Bill Clinton and Congress, shutting the government. The dispute between House Speaker Newt Gingrich, a Republican, and Democrat Clinton prompted Moody's to review some U.S. government bonds for a downgrade in January 1996.

The average price-earnings ratio in 1995 was 16.6, 15 percent below its level in 1994, data compiled by Bloomberg show. As the debate over federal spending led to two government shutdowns that year, the S&P 500 ended up rallying 5.9 percent in November and December and went on to gain 48 percent by 2000.

Upside in Equities

The reduction of the U.S. credit rating gave investors another reason to avoid equities amid uncertainty about the political and economic situation in the world's largest economy, according to Andrew Slimmon, managing director of global investment solutions at Morgan Stanley Smith Barney LLC, which has about $1.7 trillion in client assets.

"The downgrade was just one more thing that caused investor anxiety to grow," Chicago-based Slimmon said in a telephone interview. "We've come to the point where the one question to be answered now is whether we are going to have anything worse than a mild recession," he said. "If we can avoid that, then there's obviously a lot of upside in the equity market."