Based on the aggregated intelligence of 170,000-plus investors participating in Motley Fool CAPS, the Fool's free investing community, petroleum pipeline and storage company SemGroup (NYSE: SEMG) has earned a coveted five-star ranking.

With that in mind, let's take a closer look at SemGroup's business and see what CAPS investors are saying about the stock right now.

SemGroup facts

Headquarters (Founded) Tulsa, Okla. (2000)
Market Cap $1.1 billion
Industry Oil and gas pipelines
Trailing-12-Month Revenue $1.56 billion
Management CEO Norm Szydlowski (since 2009)
CFO Robert Fitzgerald (since 2009)
Operating Margin (Average, Past 3 Years) 2.9%
Cash/Debt $155.8 million / $343.9 million
Competitors Enterprise Products Partners (NYSE: EPD)

Sources: Capital IQ (a division of Standard & Poor's) and Motley Fool CAPS.

On CAPS, 98% of the 49 members who have rated SemGroup believe the stock will outperform the S&P 500 going forward. These bulls include kenjotto and All-Star XMFConnor, who is ranked in the top 10% of our community.

Just last week, kenjotto highlighted SemGroup as a particularly special situation:

… the new management seems to be on the right path. The refinancing and capital investments by themselves would be good things for this stock. But, throw in that this company will most likely convert to an MLP soon and the awesome dividend that will ensue, and this stock will have an awesome return coming soon.

Currently, SemGroup even trades at a cheapish price-to-book ratio of 1.3. That represents a clear discount to industry peers like Enterprise Products (3.1), ONEOK (3.1), and Kinder Morgan Energy Partners (NYSE: KMP) (3.4).

CAPS All-Star XMFConnor elaborates on the opportunity:

• Semgroup's bankruptcy was caused by poor management -- not the underlying business.
o The CEO essentially speculated on the price of oil -- shorting it against its huge run in 2008 which ended up bankrupting the company.
• The entire senior management team has been replaced and the business now operates as it always should have -- as a primarily fee-based midstream energy transportation company.
o Catalyst: SEMG is likely to convert to an MLP, like the rest of the major midstream energy companies. Once this occurs and SEMG gains analyst coverage over time, SEMG should trade at similar multiples to its comp group
• There could be significant additional upside given a successful credit refinancing and the use of additional leverage, in line with industry averages.

What do you think about SemGroup, or any other stock for that matter? If you want to retire rich, you need to put together the best portfolio you can. Owning exceptional stocks is a surefire way to secure your financial future, and on Motley Fool CAPS, thousands of investors are working every day to find them. CAPS is 100% free, so get started!

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.