Ivan Glasenberg
Ivan Glasenberg, the multi billionaire CEO, is thought to have lost more than $4bn over the past yearReuters

Glencore shares fell more than 22% on 28 September, the sharpest fall in the company's history, as it continues to struggle with the challenging commodities market. From around 340p just a year ago, the company has shed more than 71% in the past few months, with the share price now at a historical low of 76p.

The mining and commodity trader announced the sale of its Brazil nickel operations for $8m (£5.2m, €7.1m) as part of the company's long-term plan to dispose of non-core assets. The company sold the division to London-based Horizonte Minerals.

With copper, zinc and steel at record lows, commodity-dependent companies have weighed down stock markets worldwide, but Glencore has been struggling for more than a year. Earlier in September, the company sold 1.3 billion shares for £1.6bn after it promised to raise around £7.7bn to try and trim its staggering debt.

Glencore issued the ordinary shares for 125p each, a price almost 65% lower than its share price in September 2014. Following the announcement that the company had made a £431m loss in the first half of 2015, the trader promised to start paying off a big chunk of its £19.48m debt by suspending dividend, spending less capital and issuing emergency shares.

"The challenging environment for mining companies leads us to the question of how much value will be left for equity holders if commodity prices do not improve," Investec analysts said. "If major commodity prices remain at current levels, our analysis implies that, in the absence of substantial restructuring, nearly all the equity value of both Glencore and Anglo American could evaporate. In the current climate, debt is fast becoming the most important consideration for mining company management."

Glencore's South African multibillionaire CEO, Ivan Glasenberg, is estimated to have a 15% stake in the company, meaning he has lost more than $4bn in the past few months.