7. Amancio Ortega

Net worth: $76.6 billion

2019 gain: $17.9 billion

Amancio Ortega built his multibillion-dollar fortune running retail conglomerate Inditex, Zara's parent company, according to the Bloomberg Billionaires Index. Inditex saw record sales in the first half of 2019, up 7% from the same period last year, Markets Insider previously reported.