It's a new week, which means it's time to check the most interesting insider purchases.

After reading through numerous filings using insider tracking tool Form 4 Oracle, here are my top five this week.

The week's buying

Company

Closing Price, Nov. 6

Total Value Purchased

52-Week Change

Gartner (NYSE:IT)

$21.81

$5,336,894

15.03%

Level 3 Communications (NASDAQ:LVLT)

$3.03

$3,230,911

(45.21%)

McMoRan Exploration (NYSE:MMR)

$12.43

$8,885,500

(16.69%)

MF Global (NYSE:MF)

$30.27

$2,271,259

18.15%*

Online Resources (NASDAQ:ORCC)

$9.37

$13,775,313

(10.93%)

Sources: Fool.com, Yahoo! Finance, Form 4 Oracle, SEC filings.
*MF Global began trading on July 26, 2007.

Score one for Online Resources?
Readers who follow this column regularly know that the best sort of insider buying is done in bunches. Heating and air conditioning specialist Goodman Global (NYSE:GGL) offers an excellent example. Ten insiders were buying in August 2006, at around $12.50 a share. They've since earned a double.

When it comes to stocks -- and most everything, actually -- I don't believe in accidents. That's why I'm raising a bullish eyebrow at Online Resources, which provides technology services to banks and other financial institutions.

I don't make that call easily. Online Resources recently told investors to expect more moderate revenue growth in 2008, and that news sent its shares into a tailspin. (They're down roughly 20% since the beginning of October.)

What's more, as Foolish colleague Rich Smith points out, Online Resources has made only intermittent business progress over the past two years. Return on capital has declined from 7.2% in 2005 to 1.8% over the trailing 12 months, for example.

So it's pretty easy to understand why our 73,000-strong Motley Fool CAPS community has mixed feelings when it comes to the stock:

Metric

Online Resources

CAPS stars (out of 5)

***

Total ratings

70

Bullish ratings

63

Bull ratio

90.0%

Bearish ratings

7

Bear ratio

10.0%

Bullish pitches

9

Bearish pitches

2

Data current as of Nov. 7.

But then there's that darned insider buying. Three insiders, plus institutional participant and 10% owner Tennenbaum Capital Partners, have purchased shares since Halloween. More than $13.7 million has been spent.

What to do? Put this stock on your watch list. As much as I like bulk-rate insider buying, Online Resources has yet to prove itself. And, trading for more than 36 times expected 2007 earnings, the stock doesn't come cheap.

Level 3 could be on the level
I can't say the same about broadband operator and potential Akamai (NASDAQ:AKAM) rival Level 3, whose stock price values each dollar of revenue at $1.16 -- well below the industry average price-to-sales ratio of 2.0.

CAPS All-Star mkeszler calls that valuation unfair:

It may take a while [for Level 3] to reach profitability, but this is a company that should eventually get there in a big way. Smart investors like George Soros think so and so does the Prudent Speculator. With any luck we are near the bottom here, but I am in for the long run.

We can't know for sure whether valuation is behind insider buying at Level 3. What we do know is that there's been plenty of it. Board member Douglas Eby, an investment advisor, purchased more than 1 million shares on Monday. Fellow director John Reed then added 40,000 shares to his direct stake yesterday.

Color me intrigued -- intrigued enough to add Level 3 to my CAPS portfolio.

And that's your update. See you back here next week, when we dig through more insider deals in search of the next home run stock.

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Fool contributor Tim Beyers, who is ranked 13,004 out of more than 73,000 participants in CAPS, owned shares of Akamai, which is also a Rule Breakers pick, at the time of publication. Find Tim's portfolio here and his latest blog commentary here. The Motley Fool has a disclosure policy.