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 from the past seven days:

The Week's Buying

Company

Closing Price 12/26/06

Total Value of Stock Purchased

52-Week Change

Emeritus (NYSE:ESC)

$24.97

$341,598

24%

Enterprise Products Partners (NYSE:EPD)

$28.80

$489,991

23%

Equity One (NYSE:EQY)

$26.53

$1,089,161

10%

Penn Treaty American (NYSE:PTA)

$7.11

$33,800

(33%)

TSR (NASDAQ:TSRI)

$3.94

$40,107

(13%)

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

The voyages of the energy stock Enterprise
In the season of Foolanthropy -- shorthand for what we here call Foolish philanthropy -- managers who invest in a better world as they seek higher profits leave me intrigued. Count Dan Duncan among the list of the more interesting.

Duncan, who Forbes says is the 35th richest American, with a $7.5 billion fortune, is the chairman of Motley Fool Income Investor pick Enterprise Products Partners. In January, he pledged $100 million to the Baylor College of Medicine to help in the fight against cancer. (Duncan is also a cancer survivor.)

That's a tremendously generous gift, and it speaks volumes about Duncan as a human being. As an investor, he's proved to be equally remarkable. He began Enterprise Products with two trucks in 1968. Today, the company owns 34,000 miles of pipe and stores 175 million barrels of gas.

You'd think that after more than three decades with Enterprise and 73 years on the planet, Duncan would be ready to cash in and relax. Turns out he's doing just the opposite: He has spent $8.49 million on Enterprise stock over the past 52 weeks.

More importantly, he's recently accelerated his buying. On Friday, Duncan spent roughly $489,000 to acquire 17,000 more shares of his company. That's more than double the 7,000 shares he bought in November.

Is Enterprise really that much of a bargain? Investors participating in the Motley Fool CAPS community-intelligence database seem to think so:

Enterprise Products

CAPS Rating (out of 5 Stars) *****

Total Ratings

126

Bullish Ratings

124

Bull Ratio

98.4%

Bearish Ratings

2

Bear Ratio

1.6%

Bullish Pitches

23

Bearish Pitches

1

Data current as of Dec. 27, 2006.

Surely, it doesn't hurt that Enterprise Products has a well-funded dividend that currently yields 6.40%. Nor should a pending IPO of natural-gas unit Duncan Energy, which is expected to distribute more than $400 million to Enterprise and, thereby, its shareholders.

But as interesting as those catalysts are, fellow Fool Ted Murphy, who goes by TMFMurph in these parts, says the investing thesis for Enterprise is far more fundamental:

"Natural gas pipeline [partnership] that gets punished (erroneously) when natural gas prices go down ... but whose revenue is primarily dependent upon the volume of gas through its pipelines, not the price."

Makes sense to me. That's why I'm putting this stock on my list to investigate; it seems ripe for my thinning CAPS portfolio.

Another chapter in a book-value saga
With the volume of mail I received in response to my writings about long-term care insurance, I knew that I'd someday have the opportunity to investigate a firm trading in this lucrative market. But I never imagined it would be a problematic outfit such as Penn Treaty American.

How problematic? In August, the company stopped sales of new policies in Florida as it rushed to finish a statutory audit report for the state insurance commissioner. The moratorium lasted through mid-November.

Then there's a sensational press release from a lawyer accusing Penn Treaty of wrongly denying coverage to an 87-year-old grandmother. Part of the problem, it seems, is the policy definition of what constitutes a coverable residence. Similar complaints reached my inbox after I wrote about long-term care, but none of them specifically referenced Penn Treaty.

And now there's a flood of management buying. Between Friday and today, eight different managers have bought shares. CEO William Hunt accounted for all $33,800 in buying referenced in the table above. The other seven, all directors except for operations vice president Cameron Waite, combined for more than $200,000 in additional purchases.

Difficult though it is to get excited about a company that could be cheating a grandma, that buying is as bullish a signal as I've seen in months.

That's all for this week. See you back here next Wednesday, when we dig through more insider deals in search of the next home run stock.

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Fool contributor Tim Beyers , ranked 2,083 out of 18,381 in Motley Fool CAPS , usually favors two scoops of ice cream over the inside scoop. Tim didn't own shares in any of the companies mentioned in this story at the time of publication. Get the skinny on all of the stocks in his portfolio by checking Tim's Fool profile . The Motley Fool's disclosure policy is a strong buy.