Oil stocks, copper stocks and all other commodity stocks are trying to find a bottom, Jim Cramer told his

"RealMoney" radio show listeners Friday, noting that tech and health care were moving lower, too.

You just have to be in the four big bull markets, he said, even on a down day. He said that these markets are minerals, infrastructure, carbons (which includes oil) and aerospace.

So, even though the commodities like minerals are down, they've been zooming higher because of true, fundamental demand from fast-growing countries around the world, he said.

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Cramer said that this demand will keep prices high, so the group is attractive as it tries to find a bottom.

For example, he said that gold prices will bounce back for a number of reasons. There's lots of geopolitical tension to go around between Iran, Nigeria and Iraq. People in China, India and Iran are hoarding the metal because they're worried about their currencies. And there's not a lot of gold left in the ground.

As far as copper is concerned, he said that hedge funds may have taken too much inventory down, and there are supply problems and lots of demand from China.

People stopped mining for zinc when the prices were too low, so now there's some scarcity. And China is driving demand for aluminum through the roof.

When commodities go up in price, central banks around the world raise rates, Cramer said, because they want to make it too expensive to hoard these metals. But even with rate hikes, he believes that these commodities will stay hot.

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Tech is looking for a bottom, too, said Cramer, adding

Microsoft

(MSFT) - Get Report

and

Cisco

(CSCO) - Get Report

have led the declines.

He also said that health care still has a way to go on the downside.

Organic Growth

What would food taste like without pesticides? Cramer asked. What would it be like to eat food that has not been genetically modified by

Syngenta

(SYT)

and

Monsanto

(MON)

?

More people clearly want to eat this type of food, he said, pointing out the fact that organic food demand is growing so rapidly that

Wal-Mart

(WMT) - Get Report

wants to get in on the action.

The mega-retailer will soon stock a wide array of organic foods in order to reach a more urban and upscale customer base. In response, foodmakers are producing organic versions of their products, with

Kellogg

(K) - Get Report

making organic cereal and Kraft trying to jump into the all-natural fray.

Kraft is owned by

Altria

(MO) - Get Report

, a stock that Cramer recently sold for his charitable trust

Action Alerts PLUS because it isn't moving fast enough to split the company into two tobacco firms and a separate food company.

But these aren't the stocks he would buy on the growth of organic food sales. Instead, Cramer said to look at

Hain Celestial Group

(HAIN) - Get Report

, a natural and organic beverage, snack and specialty food company.

The stock has pulled back about 7% from its high, which makes it a good time to start buying.

For best of breed, he said to check out

Whole Foods

( WFMI), which has recovered from two disappointing quarters.

Across the Pond

Cramer reminded listeners that most people had a cool relative that allowed them to get away with stuff that their parents never would. The rules were looser at these relatives' homes, he said. And he believes that this memory helps explain what's going on with the London Stock Exchange and a lot of the exchanges in Europe.

The

New York Stock Exchange

and the

Nasdaq

want to buy the European exchanges because the rules there are not as tough on companies, he said. Since the huge scandals of the late 1990s, he said that the U.S. has become the most regulated market in the world.

Two for the Road

As a side note, the said that with

Toyota

(TM) - Get Report

down $5, it's time to start buying. This will be the largest automaker in the world, he said.

He said that

Kubota

(KUB)

is also down too much and a good buy at these levels.

"Once upon a time, there was a company that I worshipped," Cramer said, "and that company was

Intel

(INTC) - Get Report

.

But it has toppled because

Advanced Micro Devices

(AMD) - Get Report

has made a better, faster, cheaper chip.

Dell

(DELL) - Get Report

could switch to AMD chips, he said, because it is paying too much for chips from Intel.

So, he said to swap out of Intel and get into Advanced Micro.

Sticking With Ciena

Friday's first caller asked Cramer if now is the time to sell

Ciena

(CIEN) - Get Report

.

He told Cramer that he bought the stock near its five-year high above $5, and now it has fallen all the way to $3.80.

Cramer said that the company makes the platforms necessary to have video-on-demand, and that the company's management said that there is still strong demand for its fiber-switching products.

Where there is demand, there is pricing power, he said, adding that he would not give up on Ciena.

But the stock has had a huge run higher, gaining as much as 140% year-on-year, he said, and now it's up 30% year-to-date and 80% on the year. So Cramer said not to buy more of this stock all at once because it could still fall.

Cramer told a listener that

CSX

(CSX) - Get Report

is one of the best rails, and that he also likes

Union Pacific

(UNP) - Get Report

and

Norfolk Southern

(NSC) - Get Report

.

The salient thing about CSX is that it's up 40% year-to-date, which will bring out some profit-takers, he said. They've made a lot of money, the market is going down and they'll decide to lock in gains.

Even though

Nabors

(NBR) - Get Report

is being sold aggressively, Cramer told a listener that the stock is bottoming and that the company reported a beautiful quarter.

It's getting hit because the entire group has been very hot, and because of its exposure to natural gas, he said. Natural gas hit an 11-month low, which is typical in May because it's a winter product. Even so, that helped accelerate selling, he said.

As for

Aqua America

(WTR) - Get Report

, Cramer said to stay away from this stock. The company missed its numbers, and he sold it for a loss for his charitable trust portfolio

Action Alerts PLUS.

At the time of publication, Cramer was long Microsoft and Nabors.

James J. Cramer is a director and co-founder of TheStreet.com. He contributes daily market commentary for TheStreet.com's sites and serves as an adviser to the company's CEO. Outside contributing columnists for TheStreet.com and RealMoney.com, including Cramer, may, from time to time, write about stocks in which they have a position. In such cases, appropriate disclosure is made. To see his personal portfolio and find out what trades Cramer will make before he makes them, sign up for

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