Well, this is happening because the US is no longer seen as reliable as it used to be... so many countries are not just reducing their exposure to US bonds, they are moving their gold to London mostly or to thier home country. Most (some will though) are not actually physically moving it, they are selling it in the US and buying it in London, as physically moving in on a plane etc. is a logistical and securtiy/insurance nightmare. However, in a few years, it will probably go back to normal, but the world is changing... so maybe not. The reason they are moving it to London is because if everything goes south, then the UK will be the last to fall in Europe... safest place that is reliable. Trouble is, the way things are looking at the moment, it seems like the US and some other countries are essentually running a giant governmental Ponzi scheme, with the US Fed just magicing up dollars to pay off older debts, so it can borrow more to keep it all going... not sustainable.