Blue-chip stocks are mixed in intraday trading following news that credit-rating agency Standard & Poor's upgraded its outlook for the U.S. government from "negative" to "stable." With roughly an hour left in the trading session, the Dow Jones Industrial Average (DJINDICES:^DJI) is up nine points, or 0.06%.

On an otherwise quiet day in terms of economic news, many investors are casting their eyes across the Pacific Ocean to Japan, where stocks have been particularly volatile of late. This trend started at the end of last year when a new government took over, vowing to revive the long-dormant economy. Since then, the nation's central bank has undertaken an aggressive monetary policy designed to reignite inflation and spur economic growth.

While early indications suggest that the move is working -- the yen has fallen in value relative to the dollar, and inflation is beginning to tick up -- an unintended, though not unexpected, consequence has been the artificial inflation of asset prices. As I've noted, the country's benchmark stock index shot up by 80% beginning last November, only to mount an aggressive correction last month. Today, it closed higher by 5% -- a massive single-day move for a market of Japan's size.

On the domestic front, meanwhile, little is catching the financial media's attention. The one notable occurrence today was the decision by Standard & Poor's to raise its outlook on the U.S. government. Following last year's budget-ceiling debacle, S&P took away the government's "AAA" rating, and although it's leaving the U.S.' credit rating at "AA+," it now views the outlook as "stable" as opposed to "negative."

Let's be honest, though: Considering how well the rating agencies performed prior to and during the crisis, I think there's legitimate reason to question the substance of their pronouncements.

In terms of individual stocks, McDonald's (NYSE:MCD) is one of the best-performing components on the Dow this afternoon, up by 1.4% at the time of writing after the company released same-store sales numbers for the month of May. Global comparable sales at the fast-food giant rose by 2.6% in May. Here in the U.S., the figure advanced by 2.4%. McDonald's attributed the better-than-expected results to its breakfast menu, "wide range of chicken options," and the "ongoing appeal" of its value menu.

Alternatively, the worst-performing stock on the blue-chip index at the time of writing is Disney. While there doesn't appear to be a specific impetus for the move, one could infer that the monthly jobs report on Friday did little to help the entertainment company, as the unemployment rate increased marginally to 7.6%. Given that Disney provides discretionary services, the health of the American consumer is paramount to its success.

And finally, shares of Apple (NASDAQ:AAPL) are up by 0.7% this afternoon. The iPhone maker is holding its Worldwide Developers Conference today in San Francisco. Many are expecting the company to announce an overhaul of its mobile operating system, as well as a new music-streaming program to complement its iTunes Store and compete with the likes of Pandora. According to Gene Munster, a widely followed analyst at Piper Jaffray, "In a larger sense, Monday will set the stage for more measurable products over the next 6 quarters."

John Maxfield owns shares of Apple. The Motley Fool recommends Apple, McDonald's, and Walt Disney. The Motley Fool owns shares of Apple, McDonald's, and Walt Disney. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.