Caesars' diminutive float of 1.8 million shares, priced at the midrange $9 per share, opened at $9.06 per share and soared to about $16 before closing at $15.39 per share, or more than 71%. Roundy's stock was relatively flat; shares opened Wednesday at $8.50 and closed at $9 per share.

While Caesars' majority shareholders TPG Capital and Apollo Global Management LLC, with 89.7% in combined holdings, aren't selling any shares in the initial public offering, other co-investors took the opportunity to sell shares. A group of 78 various hedge funds, state pension funds and trust funds, among others, received the right to sell to public markets an aggregate of 22.3 million shares of Caesars stock in the coming months. Specifically, they could sell half their portion of the 22.3 million shares as soon as the IPO priced, and the other half in six months.

Hedge fund investor John Paulson of Paulson & Co. received a similar deal. Paulson has the option to sell his 9.9% stake (about 12.4 million shares) at any point after the IPO prices.

An immediate sale at current prices would mean up to a payout of about $186 million for Paulson, who holds 12.3 million shares. The New York financier bought into what was then known as Harrah's Entertainment Inc. in June 2010 through a debt restructuring. Paulson paid $474 million to acquire $710 million in par value debt, a 33% discount. It then exchanged that $710 million in par value debt for its 9.9% equity.

With shares trading at about $15 each, Caesars' market capitalization is about $1.875 billion and its enterprise value is pegged at about $23.5 billion. Caesars trades on the Nasdaq under the symbol CZR.

TPG, Apollo and Paulson did not return calls for comment. Caesars declined to comment, citing a quiet period.

TPG and Apollo's 89.4% stake is worth about $1.68 billion.

On the other hand, Roundy's private equity backer, Willis Stein & Partners, as well as other smaller stakeholders, will reap more profits from their investment, in spite of a somewhat disappointing debut.

Shares of the Midwestern grocery chain priced at $8.50 per share, well below its $10 to $12 per share target, raising $163 million from the 19.2 million share offering.

Willis Stein sold about 4.5 million shares, garnering about $38.3 million. It could reel in another $24.5 million if underwriters fully exercise a greenshoe option.

Including $590 million in dividends the sponsor has already received since it bought the company in 2002, Willis Stein is poised to book a 2.1 times realized return on the $314.5 million of invested equity.

Post-offering, Willis Stein will remain the largest shareholder, with 32.2%. At $8.98 per share, the firm's 13.3 million shares are valued at about $119 million.

Minority investor AlpInvest Partners BV's 4.3% remaining stake will be worth $15.9 million. Norwest Equity Capital Inc. and Northwestern Mutual Life Insurance Co. are also retaining shares.

Roundy's shares trade on the New York Stock Exchange under the symbol RNDY.

The IPO conferred a market cap of $373 million to Roundy's and an enterprise value of about $1.42 billion.