After more than a week of volatility, the stock market moved sharply higher today, with good news from both the international and domestic fronts. A rise in new-home sales helped boost spirits in the U.S., while signs of stability in Italy gave investors some confidence that Europe might be able to hold itself together and get through its current financial crisis. By the close, the Dow Jones Industrials (DJINDICES:^DJI) finished up 152 points, while the broader market saw similar gains of slightly more than 1%.

But several Dow components missed out on the gains. Perhaps the most surprising was Home Depot (NYSE:HD), which fell two-thirds of a percent despite the news from the housing market. Yet the gains on the new-home sales front weren't as large as some economists had hoped, and combined with dour news about existing-home sales yesterday, a minor drop from near all-time-high levels isn't cause for major concern yet.

UnitedHealth Group (NYSE:UNH) was the biggest decliner in the Dow, dropping more than 1%. One trend that has come out this quarter is that overall use of medical services has been on the decline, and that has hurt companies that actually provide health care. For UnitedHealth, fewer claims might actually be good news, although the shifting of health-care costs to employees and the rise in use of high-deductible plans pose potential threats to its long-term business model.

Outside the Dow, Arch Coal (NYSE:ACI) plunged 6.5% after announcing a first-quarter loss in its earnings report. Lower coal prices and weak volume caused the company to miss earnings and revenue forecasts, and as a result, Arch Coal cut its capital expenditures forecasts. With so many producers facing the same issues, the ripple effect from Arch's earnings report was palpable, as Alpha Natural Resources (NYSE:ANR) dropped more than 4%. Alpha won't report until next week, but it faces many of the same issues as Arch, and neither will fare well if the downturn in coal doesn't dissipate soon.

Fool contributor Dan Caplinger has no position in any stocks mentioned. You can follow him on Twitter: @DanCaplinger. The Motley Fool recommends Home Depot and UnitedHealth Group. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.