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, Oct. 16

Total Value Purchased

52-Week Change

Barnes & Noble (NYSE:BKS)

$37.61

$11,404,589

(2.06%)

EV Energy Partners (NASDAQ:EVEP)

$36.20

$422,830

81.07%

Main Street Holdings (NASDAQ:MAIN)

$15.02

$1,561,458

N/A*

Prospect Capital (NASDAQ:PSEC)

$16.09

$402,555

(3.67%)

Thor Industries (NYSE:THO)

$52.00

$456,457

9.39%
Sources: Fool.com, Yahoo! Finance, Form 4 Oracle, SEC filings.
*Main Street began trading on Oct. 9, 2007.

Look at all those books!
We begin with bookseller Barnes & Noble, which first appeared in this column in August 2005. Chairman Leonard Riggio hasn't earned much since.

To the contrary -- Barnes & Noble has substantially underperformed the S&P 500 over the past two-and-a-half years. No wonder our 70,000-strong Motley Fool CAPS community is relatively sour on the stock:

Metric

Barnes & Noble

CAPS rating (out of 5)

**

Total ratings

133

Bullish ratings

109

Bull ratio

81.9%

Bearish ratings

24

Bear ratio

18.1%

Bullish pitches

16

Bearish pitches

7
Data current as of Oct. 16.

Yet Riggio wants another shot. He began buying in August and has added 300,000 shares to his bulging portfolio since last Wednesday. What's he seeing that others don't?

The valuation certainly isn't cheap. Consider the numbers. Even though free cash flow has recovered from $91.9 million at the end of the last fiscal year to $262 million over the trailing 12 months, FCF remains lower than it was four years ago.

Estimates don't match up well, either. Wall Street expects Barnes & Noble to grow by 11.5% over the next five years, yet the stock trades for 20.7 times its current-year projected earnings and 18.7 times next year's estimated income.

That's not Carrot Top outrageous, but it might be Bobcat Goldthwait annoying, especially for a cheapskate growth investor like me.

Foolish colleague Alyce Lomax put it best here, I think. Quoting:

With the Potter finale behind it, can Barnes & Noble continue its success? From the numbers, it looks like Harry provided some temporary relief, but the company's future seems far less magical.

Agreed. Wait for other insiders to join Riggio's purchase party before crashing it with your portfolio. I'd hate to see your returns disappear.

The mighty Thor?
Next is RV specialist Thor Industries, which remains a highly rated stock in CAPS. All-Star TheGarcipian explained why a year ago:

Gasoline prices have never really affected Americans' desire for the open road, nor will they ever tame our infatuation to freely drive anywhere (to wit: drive-up liquor stores!). Besides, when fuel prices rise, so do airfares; so a family vacation for four will ALWAYS be cheaper when the family drives. Thor builds high-quality RVs for mid- to high-level income clients, and as Field of Dreams reminds us, they will come. And they will continue to buy.

Oh, how right he was. Thor blew away estimates last week with a 16% improvement on the bottom line, despite lower revenue in its fiscal fourth quarter. Today, investors appear to (mostly) like what they see.

But insiders are mixed. Chief Financial Officer Walter Bennett boosted his direct holdings by 30% on Oct. 5. Vice Chairman Peter Orthwein, meanwhile, sold less than 1% of his principal stake last Tuesday. Who's right?

My guess is Bennett, because he's closer to the numbers and buying more than Orthwein is selling. Nevertheless, I'd prefer to see a gaggle of buying. Without that, it's hard to be 100% bullish on Thor. Wait for lower prices, Fool, and then pounce when the discount becomes irresistible.

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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