James Ashton: Billionaire's rare level of faith in his company needs to feed through to its shares

When you're worth £4bn, what is £70m between friends? Ivan Glasenberg probably won't notice if the bumper dividend he is due from Glencore is reinvested in stock instead of taken out in cash.

But together with a pledge to forfeit his bonus and so far refrain from selling any shares, it goes a long way to demonstrating his confidence that floating the Swiss commodities giant was the start of the story for investors, not the end. This isn't quite the same as the token $1 that Steve Jobs paid himself at Apple, but you get the idea.

The trouble with being the boss and owning a large share in a business is that – your vast wealth aside – you can't win. Floating a private company, as Glencore was for many years, creates a currency for acquisitions but also lets long-serving staff finally cash in.

But if the top brass don't, it becomes a waiting game for the City, rather like the stock overhang in a business that was brought to market by a private equity backer. Disposing of a single share can spark a flurry of "sell" notes if it is handled badly and the market interprets it as the first sign of worries over trading.

The soft furnishings retailer Dunelm suffered from a hard landing yesterday when the founders' son sold £25m of stock, claiming something about diversifying the portfolio.

Glasenberg has defused the situation by pledging not to dispose of shares while he's at Glencore. It is a level of faith rarely displayed by blue-chip bosses. Even Charles Dunstone, the tycoon behind Carphone Warehouse and TalkTalk, has sold the the odd share despite showing an uncommon commitment to both.

All Glasenberg needs now is for that confidence to feed through into Glencore shares, 20 per cent down on their float price last May.

That ought to correct itself as lock-ins expire and FTSE tracker funds are forced to buy more stock. However, if he is true to his word, it won't be Glasenberg's stock they are buying.