What interests me most here are the buyers and the sellers, as they relate to a pair of  conversations we had in this space last week: The SEC’s inquiry into secondary market trading of private shares, and how this inquiry could impact Facebook’s eventual IPO.

DealBook reports that Goldman Sachs (GS) is leading the deal with a $450 million commitment, with the remainder coming from existing Facebook shareholder Digital Sky Technologies (which has a right to buy up to $75 million of Goldman’s stake). Nothing too interesting so far. But then we have this:

As part of the deal, Goldman is expected to raise as much as $1.5 billion from investors for Facebook at the $50 billion valuation, people involved in the discussions said, speaking on the condition of anonymity because the transaction was not supposed to be made public until the fund-raising had been completed.

In a rare move, Goldman is planning to create a “special purpose vehicle” to allow its high-net-worth clients to invest in Facebook, these people said. While the S.E.C. requires companies with more than 499 investors to disclose their financial results to the public, Goldman’s proposed special purpose vehicle may be able get around such a rule because it would be managed by Goldman and considered just one investor, even though it could conceivably be pooling investments from thousands of clients.

DealBook says that it “unclear whether the S.E.C. will look favorably upon the arrangement.”

My understanding of the existing SEC inquiry — and that’s all it is at this point, not an “investigation” — is that the SEC is interested primarily in two things: (1) Do funds raised to invest in specific companies (i.e., Facebook) qualify as a single investor vis-a-vis the 500-shareholder rule, or does every underlying investor count? (2) Do these funds purport to have non-public financial information upon which their underlying investors can make informed decisions and, if not, are there any investor protection rules being broken (just because you’re an accredited investor doesn’t mean you can’t get taken advantage of)?

On the first question, I don’t exactly see how the Goldman “fund” would be much different from the other Facebook-specific funds being floated out there. Given that it isn’t a blind capital pool (i.e., give us money, we’ll find investments meeting certain general criteria), it is hard for me to understand how Goldman would be acting as anything other than a broker (as opposed to a fund manager). And, as such, I’m curious how/why Goldman and Facebook think this arrangement can avoid the 500-shareholder rule.

The second question actually could be a bit more interesting. One would have to believe that Goldman did, indeed, get a look behind Zuckerberg’s financial curtain. It is true that most of the “Facebook funds” do not have access to the company’s financials, but we’re talking about an investment that could total $2 billion. I just can’t imagine that a firm like Goldman is flying blind on so much cash. What remains to be seen, however, is if it provides any of that underlying info to the clients from whom it hopes to raise the $1.5 billion.

If not, then the SEC could have the same concerns over investor protections that it has about the other Facebook funds, even though Goldman should be considered a more knowledgeable manager than the others.

Finally, let me reiterate that this investment will not necessarily precipitate a Facebook IPO — even if the SEC finds the company in violation of the 500-shareholder rule, and requires it to publicly disclose financial information. Facebook clearly has no need for capital (a prime motivator for IPOs), has plenty of liquidity options for existing shareholders and still could avoid many public company hassles outside of the financial filings (no need to meet with analysts or hedge funds, do quarterly earnings calls, etc). In fact, one even could argue this deal makes an IPO less imminent.

Not saying that Facebook won’t go public soon, just that this new investment shouldn’t really change the equation. Well, I guess that’s not entirely true. If there is an IPO filing, expect Goldman to be on the cover…