Bloomberg Jay-Z joins Blackstone in buying a stake in Certified Collectibles (Bloomberg) — Certified Collectibles Group, which evaluates and verifies objects such as sports trading cards, stamps, and coins, has agreed to be purchased by Blackstone Group Inc. Blackstone’s tactical opportunities division is buying a majority stake in the company, which is valued at more than $500 million. Roc Nation, Jay-entertainment Z’s organization, and Daryl Morey, president of basketball operations for the Philadelphia 76ers, are among the other investors. Mark Salzberg, the founder and CEO of Certified Collectibles/nRead More