Welcome back to another Foolish review of the hottest stocks as ranked at 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.

Last week, major airlines were hotter than The Donald after a lackluster ratings report for The Apprentice: Los Angeles. But not this week. Stocks that fall under the CAPS tag of Drug-Related Products are the Fools on the hill this time, up 9.3% over the past 30 days. What are the others? Have a look:

  • Pollution & Treatment Controls, which includes firms that clean up after the rest of us. Stocks of these merry environmental maids are up 9.1% over the past 30 days.

  • Internet Software & Services, which, like your friendly neighborhood Fools, provide Web-based services that inform you even if they don't amuse and enrich you. Stocks of these webbed wonders are up 7.6% over the past 30 days.

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 Stars

No. of CAPS Ratings

Bullish CAPS Ratings

Bull Ratio

MFRI (NASDAQ:MFRI)

*****

15

15

100.0%

GigaMedia

*****

326

318

97.5%

CDC (NASDAQ:CHINA)

*****

339

327

96.5%

CECO Environmental

*****

35

33

94.3%

USANA Health (NASDAQ:USNA)

*****

52

48

92.3%

Source: Motley Fool CAPS.

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

Company

CAPS Stars

No. of CAPS Ratings

Bearish CAPS Ratings

Bear Ratio

Auxilium Pharmaceuticals (NASDAQ:AUXL)

*

32

19

59.4%

1-800-Flowers (NASDAQ:FLWS)

*

62

33

53.2%

Zila (NASDAQ:ZILA)

*

15

7

46.7%

Autobytel (NASDAQ:ABTL)

*

23

9

39.1%

Source: Motley Fool CAPS.

Do you agree? Disagree? 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:

Fool contributor Tim Beyers, ranked 391 out of more than 21,000 in CAPS, didn't own shares in any of the companies mentioned in this story at the time of publication. Get the skinny on all of the stocks he owns by checking Tim's Fool profile. GigaMedia is a Global Gains pick. The Motley Fool's disclosure policy is hotter than city asphalt in the summer heat.