Money trading is one of the oldest ways of making some money really fast but it is always a gamble. In the days of the Roman Empire traders would set up tables along the streets and offer coins from far flung parts of the empire at various prices. Because some of the coins belonged to other empires, ones that were in battle with the Roman empire about to be conquered or not, depending on how the battle was going, a person buying a bag of some distant nations coins could either make a profit or end up with a bag of nearly worthless bronze.
Today the money trading markets, like Forex, are no different. Depending on the luck or lack thereof of a nation, its currency may be worth more than that of another. Unlike the money traders of Roman times, who usually knew something before setting up shop, traders can get information in real time and make split second decisions on whether to sell or buy a foreign currency.
The danger with money trading is that if it were that easy for housewives and househusbands to make millions there would be a millionaire behind every keyboard. If you fall for one of the get rich money making schemes that supposedly give you inside information on Forex trading you are falling for a scam. There is no system that can make you rich. It mostly comes down to luck. Just like gambling in Las Vegas, when you decide to pull the trigger and buy or sell Pesos or Rubles is a gamble. True, there are systems which lower your odds, but none is 100% effective and you will find that one month you are up and the next you are down. I fell for the Forex trading scam a couple years ago and found this to be the case. The kit I purchased cost $1000 and came with a "radar" that supposedly showed which currencies were coming into favor and which ones to sell. It was more like a Ouija board and only worked half the time. Be very, very careful about Forex money trading schemes and don't quit your day job.
Finally, think about this. If it were possible to profit from the demise or rise of a currency consistently then nations themselves would have a "Department of Money Trading". Russia perhaps, using sophisticated computers, spies gathering inside information and statistical experts, could make trillions off of of other countries currencies. So far we have no evidence that any country is engaged in a currency trading for profit scheme as a significant part of governmental revenue. Why? Because it is impossible to predict with any accuracy which way a currency will go. Too many factors are at play.