You've heard of the "January Effect," when investors sell stocks in December for tax reasons, only to buy them back in January, causing their price to jump.

All year long, we look at stocks that also do better in other months. For retailers, for example, some seasons are better than others, simply because of the nature of the business. So some stocks actually do best in April.

Whatever the reason, investing based solely on the calendar is certainly not a Foolish strategy. Still, wouldn't it be great to know ahead of time which stocks performed best at what times?

On Motley Fool CAPS, more than 130,000 members have weighed in on about 5,300 stocks, awarding five-star ratings to the companies that most command their confidence. We've paired some of their opinions with data going as far back as five years to see which stocks perform best in each month. The following five companies seem to do best in April:

Stock

Market Cap

Avg. % Return, April

Avg. % Return, Rest of Year

CAPS Rating (out of 5)

 

LTM Return

Verizon

$93.8 billion

1.48%

(0.31%)

****

(11.68%)

Google (NASDAQ:GOOG)

$114.9 billion

15.58%

0.77%

***

(22.77%)

Baidu.com (NASDAQ:BIDU)

$6.4 billion

27.29%

2.96%

***

(37.86%)

Boeing (NYSE:BA)

$26.6 billion

6.52%

(0.51%)

***

(49.11%)

American Express (NYSE:AXP)

$17.8 billion

3.29%

(2.33%)

***

(67.43%)

Sources: America Online, Motley Fool CAPS. LTM = last 12 months.

Something has brought profits to telecom giant Verizon in April, while the company doesn't prosper the rest of the year. Meanwhile, AT&T (NYSE:T) does better in December -- underscoring why we don't recommend simply using this as a list of stocks to buy or sell. Consider it just a platform for further research. We may need to look closer for a reason, but Verizon's four-star CAPS rating suggests investors think it's worth calling home about. Let's take a look at one of the other names above.

At the Pentagon
Considering the budget ax the Defense Department is taking to programs, Boeing might want to duck. Defense Secretary Robert Gates announced cuts that could affect the airplane maker. Thus, the F-22A Raptor, an advanced-stealth jet fighter; the C-17 Globemaster III military cargo plane; a network of vehicles, drones, and communication systems in the future combat systems (FCS) program where Boeing is the lead contractor; and other programs may be abandoned or significantly restructured.

Indeed, many of Gates' proposed cuts are directly aimed at the defense contractor's field of expertise. While Lockheed Martin (NYSE:LMT) and General Dynamics (NYSE:GD) also could be affected -- Lockheed is the prime contractor for the F-22, and General Dynamics would lose the manned ground vehicle program if the cuts are enacted -- Boeing might be hit harder. About 46% of Boeing's revenues come from government contracts, with the military aircraft segment accounting for 22% of Boeing's total revenue last year.

CAPS member SwordAgain had just these sorts of obstacles in mind, along with the weakness in the commercial aircraft side of Boeing's business. SwordAgain wrote:

3/25/09 Pitch: Downthumb. Earnings 4/22/09. Defense likely to experience major cuts. 787 program at risk of significant losses due to overweight plane (contractual penalties). Commercial airline companies cancelling or delaying purchases, not only of the 787 but also the 777. Stock is up sharply from its low on no significant positive news. Likely to retrace.

Not unexpectedly, Boeing shares took a hit on Tuesday, but these defense cuts are not a fait accompli. Congress is likely to have a large say in whether these cuts are enacted, and with unemployment already north of 8%, senators and representatives undoubtedly will be loath to allow cuts that will increase layoffs in home districts. Still, Boeing surely would experience cutbacks.

A calming effect
It pays to start your own research on these stocks on Motley Fool CAPS. Read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made -- all from a stock's CAPS page. Your voice affects these stocks, whatever month the calendar may display. It's free to sign up and express your investing opinions, so why not use this opportunity to take your star turn?

American Express is a Motley Fool Inside Value pick. Baidu and Google are Rule Breakers recommendations. The Fool owns shares of American Express. Try any of our Foolish newsletters today, free for 30 days.

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his holdings. The Motley Fool has a disclosure policy.