Mark Zuckerberg's change of heart just cost him $2.9 billion

The co-founder of the world’s largest social-media business saw his fortune fall $2.9 billion Friday after he posted plans to shift users’ news feeds toward content from family and friends at the expense of material from media outlets and businesses.

Shares of Facebook tumbled 4.5 percent Friday, cutting Zuckerberg’s fortune to $74.4 billion on the Bloomberg Billionaires Index, costing him his place as the world’s fourth-richest person.

The drop wipes out much of the $4.5 billion Zuckerberg, 33, has added so far this year. The world’s 500 richest people gained $1 trillion in 2017 and an additional $17 billion in the first two weeks of 2018, according to the Bloomberg index.