"You're losing one of the most esteemed investors one could argue of all time," a source said of investors' reaction to Buffett's plan to step down.

Berkshire Hathaway stock fell sharply early Monday on news that CEO Warren Buffett will be stepping down at year-end after 60 years of leading the company. Now, investors have to decide if it’s worth owning for the long term.

Berkshire will miss Buffett’s “clout,” said one analyst, as the company lost about $30 billion in market value following the Oracle of Omaha’s retirement announcement.