Welcome back to another Foolish review of the hottest stocks, as ranked by Motley Fool CAPS. We're looking at the three best-performing industries over the past 30 days, and your favorite long and short candidates in each.

Who says commodities are yesterday's news? Not me. One week after platinum producers rose to the top of the leaderboard -- a perch they still enjoy -- nickel and aluminum miners displaced dry bulk shippers and coal miners for second and third place, respectively.

The numbers are impressive. Platinum stocks outshone all others with a 34.5% return over the past 30 days. But nickel miners, up 18.2% as a group, and aluminum stocks, up 16.9%, still delivered impressive gains.

According to you, our Foolish readers, the best stocks in these industries to own now -- i.e., those with four or five of the maximum five stars in CAPS -- are:

Company

CAPS Rating

No. of CAPS Ratings

Percent Bulls

30-Day Price Change

Companhia Vale do Rio Doce (NYSE:RIO)

*****

3,370

98.3%

19.5%

Anglo American

*****

608

98.0%

20.1%

BHP Billiton

*****

1,719

97.9%

12.3%

Aluminum Corp. of China (NYSE:ACH)

*****

2,430

97.7%

36.2%

Kaiser Aluminum (NASDAQ:KALU)

*****

150

97.3%

16.4%

Superior Essex (NASDAQ:SPSX)

****

74

97.3%

23.4%

North American Palladium (AMEX:PAL)

****

469

94.5%

90.5%

Sources: Motley Fool CAPS, Yahoo! Finance.

And your favorite short candidates -- i.e., those rated with one or two stars in CAPS -- are:

Company

CAPS Stars

No. of CAPS Ratings

Percent Bears

30-Day Price Change

Tredegar (NYSE:TG)

**

20

20.0%

16.8%

Sources: Motley Fool CAPS, Yahoo! Finance.

My favorite this week is North American Palladium. CAPS All-Star ChrisGraley, who captured all of the last month's gains, best explained the thesis in mid-January. Quoting from his pitch at the time:

Currently Russia controls Palladium the way the Middle East controls oil. Anytime Russia feels the need to tighten the market on Palladium you should see a large spike in [North American Palladium] stock. Currently the biggest use for Palladium is as a major component in catalytic converters in automobiles. Given the increased demand for autos in China and India and global pressure on those countries to control pollution, I can only see the price of Palladium climbing in the next decade.

Then, a little more than a week ago, investor abbaman7 added, "With palladium selling for about 25% of platinum and with palladium able to act as substitute for platinum in many applications, palladium prices should continue to rise and could double within next 5 years."

I'll add that returns on capital, after more than three years in the red, turned positive over the trailing 12 months. Margins are also on the upswing, and total debt is down 24% from December 2006 to September 2007, the last reporting period for which balance-sheet data is available.

All are signs of a very healthy business. Thus, I'll be adding North American Palladium to my CAPS watch list today.

But that's my take. What's yours? Would you buy North American Palladium at today's prices? Let us know what you think by signing up for CAPS today. It's 100% free to participate.

Cap off your day with related CAPS Foolishness: