Each member of the Bloomberg Billionaires Index made an average of US$14 million per day over the past six months, according to data compiled by Bloomberg. It was the best half-year for billionaires since the back half of 2020, when the economy rebounded from a Covid-induced slump.

The gains coincided with a broad stock market rally, as investors brushed off the effects of central bank interest rate hikes, the ongoing war in Ukraine and a crisis in regional banks.

The S&P 500 rose 16% and the Nasdaq 100 surged 39% for its best-ever first half as investor mania over artificial intelligence boosted tech stocks.

While Elon Musk and Mark Zuckerberg flirt with scheduling a cage match, Tesla Inc’s chief executive officer came out on top in dollar terms. Musk, the world’s richest person, added US$96.6 billion to his net worth this year through June 30, while Meta Platforms Inc CEO Zuckerberg gained US$58.9 billion.

Gautam Adani’s net worth sank the most in the six-month period, losing US$60.2 billion. Adani, chairman of Adani Group, also posted the biggest one-day loss of any billionaire, shedding about US$20.8 billion on Jan 27, after short-seller Hindenburg Research accused his conglomerate of accounting fraud and stock manipulation — a claim Adani denies.

Hindenburg, founded by Nate Anderson, also knocked down the net worth of another billionaire: Carl Icahn. His Icahn Enterprises LP had its steepest one-day drop after Hindenburg disclosed it was shorting the shares, saying the stock was significantly overvalued relative to its holdings.

Icahn’s net worth fell US$13.4 billion, or 57% — the largest percentage drop of any member of the Bloomberg Billionaires Index in the period.

For Musk, the wealth gains spilled over into July as Tesla shares climbed 6.9% on Monday in New York, tacking on an additional US$13 billion to his fortune.