That's what central banks do: they try to use monetary policy to influence the trading price of the currency they issue. It's the least capitalist way to handle a currency near enough, besides outright pegs. Central banks exist to intervene in currency markets, not to let them function. They also now intervene in basically every financial market, not just currencies.

There wasn't a line in "1984" that said "Communism is Capitalism!", but there should've been.