Jeff Bezos regained his spot as the world's fourth-richest person.
Jeff Bezo delivers remarks at the grand opening of the new Washington Post newsroom in Washington, Jan. 28, 2016. Reuters/Gary Cameron

For months now, Jeff Bezos and Carlos Slim have been neck and neck in the competition for world's fourth-richest person. On Thursday afternoon, the founder overtook Slim, owner of major phone company America Movil SAB, once again, after Amazon reported first-quarter earnings and sales that sent share prices soaring from $602 to as much as $683.

Bezos' net worth hit $60 billion as a result, even as Slim's dropped to $55 billion (a $3.4 billion decrease) after his company reported slimming profit margins, Bloomberg reported, based on its billionaires index. The top three, according to Bloomberg, are Microsoft co-founder Bill Gates, Spanish fashion tycoon and Zara chain owner Amancio Ortega and investor Warren Buffett.

The first time Bezos' net worth surpassed Slim's was in November 2015. Then, in February, Slim took the lead, their paths crossing somewhere around the $50 billion mark. Slim maintained that position by a head for several weeks, but then widened the gap over the next several weeks, at one point beating Bezos by around $8 billion. The gap began to narrow in the last week of March, until earnings reports this week put Bezos back in the lead.

After Mexico City-based America Movil SAB's reported earnings Wednesday fell short of analysts' expectations, its share price dropped 11 percent and wiped out $3.4 billion for Slim, the largest holder of the company's stock. (He is now estimated to hold wealth of $55.2 billion.) The largest wireless carrier in Latin America, Movil reported profit margins of 35.7 percent, down from 41.7 percent the year prior, as it struggles to weather competition and regulatory changes within telecommunications.

Seattle-based Amazon, on the other hand, reported net income of $513 million for the first quarter on revenues of $29.1 billion for earnings of $1.07 per share. Analysts had projected earnings of 57 cents and $28 billion in revenue. The company cited demand for its new rapid delivery options and its hard tech, like the Kindle, as helping to boost sales.