Hershey Trust Co. is a rarity in corporate America. It owns almost all of Hershey Co.’s Class B stock, giving it roughly 80% of the voting power of the company. That clout was apparent this week when it rebuffed a takeover attempt by Mondelez International Inc.

Snack-food giant Mondelez International Inc.’s potential takeover of chocolate maker Hershey Co. would rank as the year’s top M&A deal. Most Read from BloombergBrace for a Nationwide Shuffle of Corporate HeadquartersCloud Computing Tax Threatens Chicago’s Silicon Valley DreamA Chicago Skyscraper Cements the Legacy of a Visionary Postmodern ArchitectSan Francisco,

Shares of Hershey Co. booked a double-digit percentage gain on Monday after Bloomberg reported that Oreo maker Mondelez International Inc. was exploring a possible acquisition of the iconic chocolate company.