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

But what about other months? Especially this month, known for its past (and current) market craziness? Well, despite current evidence to the contrary, some stocks do better in October than in other months.

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

On Motley Fool CAPS, more than 115,000 members have weighed in on more than 5,400 stocks, awarding five-star ratings to the companies that best command their confidence. We've paired 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 October:

Stock

Market Cap

Avg. % Return-Oct.

Avg. % Return-Rest of Year

CAPS Rating
(5 max)

Return (YTD)

Synaptics (NASDAQ:SYNA)

$863.1 million

26.30%

1.98%

****

(6.71%)

RealNetworks (NASDAQ:RNWK)

$533.4 million

10.70%

(0.75%)

**

(38.59%)

Nuance Communications (NASDAQ:NUAN)

$2.2 billion

19.00%

1.13%

****

(47.81%)

Zix (NASDAQ:ZIXI)

$110.3 million

41.66%

(3.47%)

****

(62.17%)

SunPower (NASDAQ:SPWRA)

$3.5 billion

37.00%

3.23%

**

(68.60%)

Sources: America Online, Motley Fool CAPS.

What's driven the outsized October performance of RealNetworks, for instance, while it basically skips a beat for the rest of the year? Considering Apple (NASDAQ:AAPL) also does well in October, maybe it's kids downloading songs from Rhapsody or iTunes while heading off to school that sends their stocks upward. We'd need to look closer for the reason, but RealNetworks' two-star CAPS rating suggests investors think it's a possible horror show. The uncertainty about causes is just one reason why we don't recommend using this as a list of stocks to buy or sell -- just a platform for further research. But if October really is the month these companies scare up growth, let's see which of them might live up to that promise.

Boo!
Though three-quarters of Zix's revenues come from email encryption services, many investors continue to look to the potential of its electronic prescription service as the future growth driver for the company. But some investors remain skeptical of Zix ever amounting to much. It hasn't been profitable since 1998, and earlier this summer CAPS member dabmu scoffed at the idea that it would turn a profit any time soon:

How does this scam still keep fooling people after a decade of empty promises? They toasted more than $300 million since inception... [Zix] is an overpromising train wreck and always has been. Read back through their years of "profits soon" PR's and you will see for yourselves.

Yet in affirming its guidance for the quarter for as much as $7 million in revenues, Zix stated that its cash balances remained stable at $13 million against no long-term debt and that it exceeded the projected number of prescription service deployments by 38%. It's that business that has CAPS member biovestor thinking there will be a future here, while at the same time admitting the speculative nature of the play. "A speculative play on e-prescribing in addition to a secure email business for health care and financial institutions."

Nuance Communications is another company that hasn't achieved profitability for several years but has a strong backing among CAPS members. While the company has seemingly created a mini cottage industry out of acquiring rivals in the speech recognition field, it has partnered with Microsoft (NASDAQ:MSFT) to create the Sync technology now found in Ford cars. But voice recognition cuts across many fields and CAPS member eightzeroes thinks the Dragon line of software will continue to lead Nuance ahead:

The wireless sector has been experiencing growth and I suspect that Dragon NaturallySpeaking from Nuance will cutting costs and time in the medical, law, and other sectors.

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 show. Since it's free to sign up and express your investing opinions, why not use this opportunity to take your star turn?

Nuance Communications is a Motley Fool Hidden Gems selection. Microsoft is an Inside Value pick. Apple is a Stock Advisor recommendation. 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 here. The Motley Fool has a disclosure policy.