After all, new york is the largest financial center in the world, and everyone on Wall Street knows it. But in the field of foreign exchange, I remember reading a book that London is the largest foreign exchange trading center in the world, probably because London has a long history of financial development, relatively little control over the money market and a relatively perfect legal system. In a word, between London market and new york market, the foreign exchange market is the most active and the exchange rate fluctuates the most.