As you may recall, Groupon did a highly unusual stock deal about 10 months before its November 2011 IPO.

The company allowed its early investors to cash out big, selling $946 million-worth of stock to a host of new investors who were eager to get in on one of the fastest-growing companies in history.

This deal was a bonanza for early Groupon insiders and investors, including Chairman Eric Lefkovsky, who banked $318 million (to go with an earlier $67 million cash-out) and Andrew Mason, who took out a total of $31 million in that round and a prior round.

Importantly, the investors who bought this pre-IPO round weren't idiots. Rather, they were a who's who of smart money.

That pre-IPO cash-out was done at a split-adjusted share price of $7.90.

About 10 months later, Groupon went public at $20 a share. The stock soared over $30 the first day, and then settled in the low $20s. Then it began a slide that culminated in last week's close of $4.75, a shocking 75%+ below the IPO price.

Last week's closing price is also well below the price Groupon's last round of private investors paid in December 2010--almost 40% below it, in fact.

So the smart money that bought in that round is looking kind of dumb.

But a fair bit of that smart money, not surprisingly, is already long gone.

Andreessen Horowitz, one of the firms that participate in the late 2010-early 2011 cash-out sold its stake in June, the Wall Street Journal's Shayndi Raice and Shira Ovide report. Groupon's stock had been cut in half from its IPO price by then, but the late-round investors were still modestly in the money. Andreessen Horowitz made nearly $14 million on its $40 million investment.

$14 million isn't chump change, but it's also not the sort of return that Andreessen Horowitz is used to getting on its investments. And the firm's decision to dump Groupon's stock, which followed Groupon's decision to ignore Andreessen Horowitz partner Marc Andreessen's advice to the company that it not go public until it was more mature, isn't a vote of confidence for the future of the company.

Other late-stage Groupon investors who have since dumped stock, the WSJ reports, include:

Maverick Capital

Fidelity

Swedish investment firm Kinnevik

Those folks did not make as much money on Groupon as they might have hoped, but they don't appear to have lost much money, either.

But then there is the smart money that has not sold its Groupon stock and is therefore taking it in the teeth along with every other Groupon investor.

This group includes several marquee names:

Those last two firms, of course, are mutual-fund firms. So if you own Morgan Stanley or T. Rowe funds, you may have had the pleasure of getting blown up in Groupon.

T. Rowe and Morgan Stanley, it's also worth noting, were huge IPO investors in Facebook--and have since gotten demolished in that stock, too.

Which serves as a good reminder that sometimes even the smart money ends up looking dumb.