It's time to check the most interesting insider purchases for the past week. After reading through numerous filings using insider tracking tool Form 4 Oracle, here are my top five today.

The week's buying

Company

Closing Price July 16

Total Value Purchased

52-Week Change

Ascent Solar (NASDAQ:ASTI)

$9.63

$17,840

3.3%

Bankrate (NASDAQ:RATE)

$25.88

$319,988

(48.9%)

MSCI Barra (NYSE:MXB)

$31.75

$2,865,330

21.6%

Steelcase (NYSE:SCS)

$9.26

$19,500

(50.6%)

Stericycle (NASDAQ:SRCL)

$55.71

$5,894,247

26.4%

Sources: Fool.com, Yahoo! Finance, Form 4 Oracle, SEC filings.

Rating Bankrate
I'm optimistic about the market. Crazy? Perhaps. It's likely my numbers aren't better than yours. Overall this year, the Beyers family portfolio was down 6.4% through yesterday. The good news: That easily bests the 15.2% hit the S&P 500 has taken. The bad: Down is down, and there's little consolation in knowing you're losing less than the index. So why am I optimistic? Like me, insiders are buying.

Our Rule Breakers stocks, in particular, are attracting stock shoppers. Witness the insiders at Sigma Designs (NASDAQ:SIGM). Last week, they spent $14,400 on shares of the beleaguered maker of chips for digital video, including Blu-ray.

But Sigma gets five stars at Motley Fool CAPS. Bankrate -- a recommendation of Rule Breakers -- isn't so fortunate. Those in our 110,000-strong CAPS community who have rated the stock give it just two stars:

Metric

Bankrate

CAPS stars (5 max)

**

Total ratings

258

Bullish ratings

197

Percent bulls

76.4%

Bearish ratings

61

Percent bears

23.6%

Bullish pitches

24

Bearish pitches

11

Note: Data as of July 17, 2008.

Insiders disagree. Chief Financial Officer Edward Dimaria bought 2,500 shares on Friday. Board member Peter Morse followed on Monday, acquiring 10,000 shares at $25.56 apiece. Interestingly, Morse was a seller at just less than $50 a share in November.

My guess is that he's buying now because he senses a bargain. If so, he's not alone. Top mutual fund investors such as Ron Baron of Baron Growth (BGRFX) and Jason Votruba of UMB Scout Small Cap (UMBHX) also have meaningful positions in the stock. Perhaps it's time to join them.

A buying twist that a contortionist would love
MSCI Barra is, in some ways, like The Motley Fool; it's an information provider for investors. Most of its clients, however, are institutions such as mutual funds.

What's interesting here is that there's a high volume of concurrent buying and selling at MSCI Barra. CEO Henry Fernandez and Chief Operating Officer David Brierwood were buying last week. Business development head Gary Retelny was selling at the same time. Buys outstripped sells by $2.8 million. Nevertheless, I'm rarely excited to see the lead sales guy selling.

What's more, Morgan Stanley (NYSE:MS), the majority holder of MSCI Barra stock, announced two weeks ago -- before the buying -- that it would sell 23 million shares. We now know that its offering price is $32 per stub, roughly equal to the prices insiders are paying (and getting).

So is the action bullish, or bearish? For me, it's too early to call. Continue watching this stock; if insiders continue to buy, consider following. If not, well ... you know the answer.

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

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This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.