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However, in my experience, no strategy is always profitable, so it's important to learn a variety of strategies to use when your usual ones no longer produce results, so we only change strategies when we haven't found one that suits the current conditions.
I like this one, and I really aggree. No strategy will ever work 100% as we desire, as its success depends on circumstances. A current strategy might not be suitable next month, and so on. Strategy is dynamic and adapts to circumstances. Strategy is about managing our choices, not determining the outcome. Therefore, if anyone claims their strategy is 100% successful, it's simply hype and should be ignored.
I also agree with you, no strategy is really sure, there is no strategy that can ever guarantee you profit, because the market or situation is never the same. You have to understand the market situation, do research and make decisions according to the changes in the market. You cannot always rely on only one strategy, you have to change your strategy according to the market situation, it is never reasonable to blindly rely on a specific strategy, because today's effective strategy can be the cause of tomorrow's failure, so you have to change your strategy at the right time and trade with the right strategy.