It's a new week, and that 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 7/24/07

Total Value Purchased

52-Week Change

Encore Bancshares (NASDAQ:EBTX)

$22.25

$1,867,193

(1%)*

Goodrich Petroleum (NYSE:GDP)

$29.08

$875,406

(15%)

Mercantile Bank (NASDAQ:MBWM)

$20.86

$238,777

(45%)

Piper Jaffray (NYSE:PJC)

$48.66

$155,660

0%

Western Alliance Bancorp (NYSE:WAL)

$24.19

$3,358,383

(32%)

Sources: Fool.com, Yahoo! Finance, Form 4 Oracle, SEC filings.
*Encore Bancshares began trading on 7/18/2007.

Paying the piper might pay off
We Fools often have fun at the expense of the big Wall Street brokerage firms. But not today. There's nothing funny about what's going on at Piper Jaffray.

Consider its CAPS record. Only 42% of the broker's picks that we're tracking are in the green. And some, such as last summer's thumbs-down pick of SGX Pharmaceuticals (NASDAQ:SGXP) -- which has since more than doubled -- have been just plain awful.

Piper's overall business hasn't fared too well, either. Last week, it reported earnings that were well below the estimates of its white-shoe peers, and the news sent the stock on a downward spiral that it has yet to pull out of.

CAPS investors can't claim to be surprised. Those who follow the Piper in our Motley Fool CAPS investor-intelligence database aren't huge fans.

Metric

Piper Jaffray

CAPS stars (5 max)

**

Total ratings

33

Bullish ratings

27

Bull ratio

81.8%

Bearish ratings

6

Bear ratio

18.2%

Bullish pitches

0

Bearish pitches

0

Data current as of 7/24/2007.

Will this broker really break you? I see some strength underlying the bad news in the latest earnings report. For example, equity and equity-linked financing fees rose 51% during the second quarter, thanks to 34 public offerings worth $4.5 billion.

But that's nothing new. Equity financing was up 53% during last year's third quarter. Obviously, Piper is going to get more than its share of underwriting deals. Meanwhile, its advisory-service fees, which suffered in Q2, are likely to bounce back.

Or at least that's what Piper's peers think. Here's how Goldman Sachs (NYSE:GS), a Wall Street wonder in CAPS, put it in a recent research note: "Financial advisory is lumpy. We believe these weak numbers are more the result of deal closings than any fundamental weakness in the environment or Piper's pipeline."

Piper's management seems to agree. Last year, members of the management team were repurchasing shares for the company. This year, they're buying for their own portfolios. Directors Samuel Kaplan and Frank Sims are the most recent buyers. They've put up more than $150,000 since Thursday to buy stock.

Color me intrigued -- so much so that the only thing holding me back from adding shares to my CAPS portfolio is Piper's ugly 3.69 PEG ratio. That's well above the industry average of 1.53 -- a bad sign -- and it's a far cry from the 0.72 Goldman sports. Better to keep this one on the Watch List for at least another quarter.

That's all for now. 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 2,438 out of more than 60,000 participants in CAPS, didn't own stock in any of the companies mentioned in this article at the time of publication. Find Tim's portfolio here and his latest blog commentary here. The Motley Fool has a disclosure policy.