In the simplest terms, before you begin to argue, let's look at the facts:-
The central banks are all privately owned and thus can print or create digital money out of thin air whenever they like.
If we just take the UK for example, which is considered by many to be a worldwide banking center, the City of London Corporation (just over the inner square mile) is also private owned and this of course is where all such banks are situated. Not only that but they have the power to make their own laws independent of the UK and even have their own police force etc... The same antidemocratic control system can be found in most major countries of the world.
The precious metals markets have been a complete joke for years as such people make use of the 'paper' markets in such commodities in order to manipulate the price (which has nothing at all to do with the actual physical trade in such markets). As the crypto market is much smaller in comparison, it is thus very easy for them to control it. The total market cap for cryptocurrency is currently around $381 Billion which is literally peanuts to them as they could create that digitally out of thin air then buy a load of bitcoin to pump the price and so make money on the way up and then dump and short the market and make money on the way down before inevitably buying back in again. There is absolutely no risk or cost to them as these private individuals created the funds by 'magic' as it were. However, such investments create real world gains and line the pockets of the rich elite trillionaires to maintain their extravagant lifestyles.
In short, the whole system is a complete joke and who is the ultimate loser? The small investor who gets caught in the middle and panics or has their stop-losses triggered as these big whales swallow all such tiny fish up.
https://steemit.com/london/@thecontrolsystem/have-you-even-heard-of-the-city-of-london
https://steemit.com/news/@thecontrolsystem/do-you-trust-the-mainstream-media
https://www.bloomberg.com/news/articles/2016-12-08/deutsche-bank-records-alleged-to-show-banks-rigged-silver-prices
http://uk.businessinsider.com/ubs-hsbc-silver-market-rigging-lawsuit-2016-12
https://news.goldcore.com/uk/gold-blog/bank-england-rigging-libor-gold-market/