The big forex bluff: getting rich or enriching others?

One could imagine the forex market as the lake's level of the water. If there were no other parameters than the meteorological ones, forecasts, or at least, trends would be fairly reliable. When it rains, it's easy to foresee that the level will rise, while in dry days it will drop. But let's suppose that a dam from a hydroelectric enterprise (banks, financial systems, big speculators) has been built upstream of the lake, and therefore their choices, which will be dictated by their economic interests, will go to determine the lake level. And therefore, beyond the knowledge of weather forecasts, it is also necessary to know what the intentions or interests of the hydroelectric company are. Suppose, however, that every inhabitant of the lake and its surroundings (small investors) can pick up or throw water into the lake through tanks. One inhabitant would have no impact on the lake level, but if we think millions of people live around the lake then their action will also have an important influence in determining the lake level. And at this point, who wants to make predictions, should also understand the tendencies of lake dwellers. We add that sometimes the earthquakes and terrorist attacks (random events) could blow the dam and pour large amounts of water into the lake, raising the level suddenly or that a nearby volcano could erupt of the lava . Suppose, moreover, that the local newspaper publishes every morning the news about the weather forecasts, the economic performance of the hydroelectric company, polls and opinions of citizens with forecasts of the level that could reach the lake, or on the state of the volcano Or the security of the dam itself. These elements will also have to be taken into account for the dam level forecasts. Now, it is natural to ask, what about all of these elements, apart from the former, is predictable? Still, the overwhelming majority of Forex texts tell us about techniques to spot currencies, as if our lake was actually a simple puddle that fills it when it rains and dries on sunny days.