There’s a trillion dollar gold club. And it wants more members

The world's largest trading centre for *actual* gold bars is in London. The market is worth $6.8 trillion (that's t-r-i-l-l-i-o-n) a year, and it's all controlled by five banks. They're now changing their rules so more people can join.

What it means: There's 7,841 tonnes of gold stored in vaults under the City of London. If people want to buy and sell gold – it's seen as a pretty stable investment – the majority of them will do so through the London Bullion Market. The transactions will be cleared by those five banks.

It's a secretive club (has anyone else got a Gringott's-like mental image) and since the financial crisis, it's been under pressure to let more banks in and to be more transparent. It's already announced how much gold is involved (that's that 7,841 figure), and is collecting data on how much is actually traded.

Gold What's this?  doesn't have the same importance to our economies any more – it used to be the basis for all currencies. But there's still a huge amount of money swilling around in the precious metals trade and the new rules are trying to make sure that market is a bit fairer.