What a difference a year makes. Just months ago, in the wake of Ferrexpo's June flotation in which Kostyantin Zhevago sold off a 27.5 per cent stake, Forbes dubbed him the world's youngest self-made billionaire, writes Michael Kavanagh .

But even oligarchs such as Mr Zhevago, who sits as deputy in the Ukrainian parliament, need to borrow money sometimes - hence the debt held by JPMorgan Chase that was redeemed.