"The bigger they are, the harder they fall." It's the worst nightmare of every investor in today's market -- buying a rocket stock just before it takes a nosedive.

Now I readily admit that sometimes, stocks rise for a reason. But sometimes, the rise becomes the reason. No matter how often we caution them not to, investors do have a habit of buying "hot" stocks, and trusting momentum to keep 'em moving upward.

Problem is, if the price goes up too much, even a great company can turn into a lousy investment (and if the company was less than great in the first place ...). Below, I list a few stocks that may have done just this. Stocks that, according to the smart folks at finviz.com, have more than doubled over the past year, and just might be ripe to fall back to earth.

Company 

Recent Price

CAPS Rating (out of 5)

Standex International (NYSE: SXI)

$25.79

*****

Continental Airlines (NYSE: CAL)

$22.04

*

UAL Corp (Nasdaq: UAUA)

$21.08

*

Companies are selected by screening for 100% and higher price appreciation over the last 12 months on finviz.com. Five stars = highest possible CAPS rating; one star = lowest. Current pricing provided by Yahoo! Finance. CAPS ratings from Motley Fool CAPS.

To the moon, Alice!
Now, clearly, any stock that doubles in a year is going to have its fans, and these three are no exception. Over on CAPS, AGCAPS pegged Continental as an outperformer more than a year ago after having problems trying "to set the dates to travel since all dates choose by me where already booked. I checked other airlines but the price was almost double than what I paid." Fully booked planes sounded like a good thing to AGCAPS; competitive pricing even better; and when paired with an observation that "insiders bought shares last month," it seemed like a good time to buy. (And it was. AGCAPS's pick has beat the market by a 120 percentage-point margin already.)

Likewise with the company that hopes to buy Continental. CAPS member faraim tells us that: "UAL Corp. has seriously leaned out the business. They cut back on premium cabins enabling a higher PRASM, have Continental in Star Alliance, and simplified the fleet."

And yet, perhaps remembering Warren Buffett's advice against investing in airlines -- any airline -- most Fools remain leery of the industry as a whole, and these two stocks in particular, giving each just a single, solitary CAPS star. But fear not, dear Fool. There is one stock on today's list that "stands" head and shoulders above the crowd ...

The bull case for Standex International
Never heard of Standex? Allow CAPS member Simbalion200 to introduce you: 

Standex International Corporation is a manufacturer of a variety of products and services for diverse industrial market segments. The Company has five operating segments: Food Service Equipment Group, Air Distribution Products Group (ADP), Engraving Group, Engineering Technologies Group, and Electronics and Hydraulics Group. ... Company has positive earnings over the last five quarters. Stock price have increased 184% over the last year. Price upward momentum will continue.

Kitchen appliances? Engraving? Hydraulics? If you're getting the impression that Standex is what we call a "conglomerate," then you're right on target. In fact, that's a large part of the reason that Joker1001 recommended the stock nearly two years ago, calling Standex a "Good 'small' conglomerate. Diversified holdings, from commercial restaurant equipment to aerospace components."

Now, when you think "conglomerate," it's ordinarily giants of industry like General Electric (NYSE: GE) or United Technologies (NYSE: UTX) that come to mind. Giants whose very size testifies to the success of the idea of pulling together multiple disparate business lines under one roof, such that when one business falters, the others can pick up the slack. As business models go, it may not sound as sexy as the elusive "pure play" on a growth sector, but it can work.

Boring is beautiful
And as Standex demonstrates, it can sometimes work very well indeed. Like Standex's April Q3 report for example. Standex managed to produce sales growth in four of its five top business lines -- Engraving (up 1.5%), Food Service (2%), Electronics (8.4%), and Engineering (13.9%).

The Engraving Group's performance is especially interesting, inasmuch as the CEO ascribed it to "strong automotive mold texturizing program work in both North America and Europe." Seems the rebound in auto sales is starting to make itself felt beyond the Detroit city limits, as Ford's gain assuages the pain of companies like Standex that depend on a healthy auto industry for their own profitability. In this regard, Standex tells us that while its "overall end user market conditions remain very challenging, our outlook continues to improve."

Foolish final thought
Call me an optimist, but I think the outlook for this stock looks pretty good as well. Standex may not have the stature of bigger conglomerates like GE or UTC -- but neither does it carry their price tags. Selling for just 12.5 times trailing earnings, and boasting free cash flow of nearly $40 million over the past 12 months (enough to pay off its net debt within about 18 months' time if it so chose), Standex shouldn't need to grow much faster than the mid-to-high single digits in order to make this stock a bargain.

Of course, that's just my opinion. You, however, are certainly free to disagree. And if you do disagree, here's your chance to tell us why.

Ford Motor is a Motley Fool Stock Advisor pick, but Fool contributor Rich Smith does not own shares of any company named above. You can find him on CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked No. 413 out of more than 165,000 members. The Fool has a disclosure policy.