Hurray for the British and the intelligence units who this week thwarted a planned terrorist attack. The plotters reportedly were planning to blow up as many as 10 different planes after those planes had left London's Heathrow Airport.

Although potential terror attacks cause oil prices to rise and increase security costs, the market has shown the ability not to be roiled by them. It would take the destruction of significant infrastructure and the killing of innocents, as happened on 9/11, to also bring down the markets.

We are definitely safer, but we're still not safe. It is hard to defend yourself against people who are willing to take their own lives just to take yours. However, one stock certainly benefited from the news about the thwarted attacks, and I believe it still has a lot of upside.

That company is

American Science and Engineering

(ASEI)

, which I own. Its shares took a big hit this week from disappointing earnings, going all the way down to $36.03. I first

recommended, and bought, this stock when it was in the high $50 range, but it has gone significantly lower since.

Immediately after the latest terror attack was thwarted, however, shares jumped from their lows and into the mid-$40 range. The market realizes that security is a big part of our world for the foreseeable future. I'll admit I was early getting into the stock, but I still own it and think it's a solid pick.

ASEI makes several security screening devices. The one that may benefit the most in the aftermath of the latest thwarted terror plot is the company's airport security screener. It takes X-rays of travelers but blocks out private body parts so as not to invade their privacy. Using ASEI's proprietary Z Backscatter technology, the system is able to detect many more types of threats than metal detectors can.

ASEI also is offering the new Gemini parcel system, which takes X-rays of packages. Gemini bolstered the company's order backlog to the tune of $63 million, a 21% increase. What's more, the company has a Z Backscatter van that can check the contents of other vehicles, detecting whether bombs, drugs or people are inside.

The best thing about ASEI is that its stock, in my opinion, is undervalued. The company has predicted future growth of 20%, with a forward price-to-earnings ratio of about 12. ASEI has more than $10 per share in cash, with a little more than $1 a share in debt.

In this world of terror attacks, one of the best screening companies is trading at a discount. The stock is still 50% off its 52-week high. I believe ASEI is a great way to play the need for increased security infrastructure.

Another stock that went on a wild ride this week was

Xethanol

TheStreet Recommends

(XNL)

, which I have owned for some time. I have

recommended Xethanol for a while as well, although I'm sorry to say it's trading below where it was when I first recommended it.

This week was something out of the Wild West for Xethanol. A new blog, ShareSleuth.com, accused Xethanol of being a sham, which caused its shares to tank. Xethanol answered those claims this week, and the stock regained a significant amount of the losses. Shares rose more than 10% Friday to $5.63.

What is awful about this blog is that its owner, Mark Cuban, readily admits that he has been shorting the stock. I beg these people to not to be so egregiously transparent about their lack of ethics. Real money is at stake, and I would dare say this article could end up in front of those public servants who wear robes and carry gavels.

I have met Cuban a couple of times, and I like him. I just can't believe he would allow something that seems so highly unethical. (

Editor's note: TheStreet.com's Marek Fuchs addressed this same issue in his latest Maven column.

)

While I could explain why the list of charges was wrong, Xethanol has already done a good job of

answering them publicly.

Suffice it to say that Xethanol does produce ethanol (at a rate of 450,000 gallons per month at a profit of 50 cents per gallon) and has announced that it will be country's first commercial producer of cellulosic ethanol by next April.

If Xethanol produces it merely sometime in 2007 then it will still be first, and this stock will take off like it has ethanol rocket fuel attached to it.

Remember,

being poor is bad, staying that way is stupid.

At the time of publication Layfield was long American Science and Engineering and Xethanol, although holdings can change at any time. A former All-American offensive lineman at Abilene Christian University, John Layfield played professional football for the then-Los Angeles Raiders and later in the World League. After wrestling in Japan, Mexico and Europe, Layfield arrived in the WWE in the mid-1990's. A former WWE champion, JBL was a featured wrester at WrestleMania 21 and can also be seen on Friday Night SmackDown! on UPN. Outside of the ring, JBL is a self-taught investor who was recruited to write a personal finance book, Have More Money Now, which was released in the summer of 2003. He has appeared on finance shows on CNN and Fox News Network. He is co-chairman of the Smackdown Your Vote! Campaign and he has joined both the USO and Armed Forces Entertainment (AFE) for tours through Iraq, Afghanistan and other Middle East countries. He regularly visits the Walter Reed Army Medical Center and the Bethesda naval hospital to meet with wounded troops.