Not that long ago, SPACs (special-purpose acquisition vehicles) were considered a backwater on Wall Street. For the most part, it was the domain of small-time underwriters.

SPACs are also known as "blank check offerings." Basically, with this structure, a shell company raises money via a public offering and then attempts to buy a company.

Well, the legitimacy of SPACs got a big boost this week. Goldman Sachs (NYSE: GS) is the underwriter on a new offering, called Liberty Lane Acquisition Corp. The goal is to raised about $350 million in a SPAC deal.

Interestingly enough, Goldman is putting a unique spin on the structure. For example, the management team will put up only 1% of the initial capital. At the same time, they will take a relatively smaller take of the profits (7.5% versus the normal 20% carry). What's more, Liberty plans to issue units that will consist of one share of the common stock and a half warrant (typically, there is one warrant per unit).

Over the past few years, we've seen a flood of special purpose acquisition company offerings (or SPACs). Basically, these are public companies that raise money to pursue acquisitions. It's a way to provide targets with some liquidity as well as a public vehicle (to do things like buy other companies).

Well, today Alternative Asset Management Acquisition Corporation (AMEX: AMV) – which is an SPAC – announced that it is merging with Halcyon, which is an alternative asset manager (founded in 1981). The deal comes to about $974 million (including $505 million in cash and notes).

Halcyon, which manages $11.5 billion in assets, operates a variety of hedge funds. In fact, some of its strategies focus on "stressed/distressed" debt categories, which has become a popular spot lately.

Then again, as seen with other publicly-traded alternative assets managers – like Blackstone (NYSE: BX) and Och-Ziff Capital Management (NYSE: OZM) – it's been challenging.

In today's trading, Alternative Asset Management's stock price is up about 2.15% to $9.50 (keep mind that the company went public at $10 per share).

Tom Taulli is the author of various books, including The Complete M&A Handbook and The Edgar Online Guide to Decoding Financial Statements. He also operates DealProfiles.com.

Equities are ailing. And yes, the IPO market is basically dead.

But there is a bright spot: Special Purpose Acquisition Corporations (known as SPACs). Essentially, this is a new-fangled public offering.

So, what's going on here?

Well, I had a chance to interview Andre Peschong, who is a veteran investment banker and has his own blog, Deal Flow Diaries.

What is a SPAC? The structure?

A SPAC is really an updated and cleaned up version of the old blind pool or blank check company. Basically, these SPACs are formed around qualified management teams that typically have a depth of knowledge in certain areas of business or industry. The SPAC structures are all fairly uniform but of late have been changing due to a number of items, such as market conditions, investor demands and SEC regulations.

The management team usually buys into the SPAC for some nominal amount -- relative to the total raise -- and receives for that a "promote," which is their equity benefit. That promote is not more than 20% and can actually be scaled back relative to getting a transaction closed.

Blank-check IPOs have been on the rise recently. There are companies that conduct initial public offerings for the sole purpose of raising capital to acquire other companies. American Apparel (AMEX: APP) recently went public in this manner.

Historically, Nasdaq listing standards have barred these companies from the exchange, which has been a big boon to the otherwise-struggling AMEX. Now the Nasdaq is proposing a new rule to the SEC that would allow SPACs to list on its exchange.

In the press release announcing the plan, Nasdaq Senior Vice President Bob McCooey said that "Acquisition vehicles are an increasingly common capital-raising device. We believe that listing them on Nasdaq, subject to these important investor protections, will benefit investors and issuers alike."

Maybe this is the right move, but it's interesting that Nasdaq was willing to stand by its principled objection to these entities until the amount of money they raise (and fees/trading volume they can generate) grew too big to ignore.

But I still think investors should be very skeptical of investing in these situations. How exactly do you research an investment in a company when you don't yet know what the business model is?