As you perfectly expressed, "efficient market" is nothing more than an hypothesis. In fact, it has been proven essentially false repeatedly, theoretically by Ka

As you perfectly expressed, "efficient market" is nothing more than an hypothesis. In fact, it has been proven essentially false repeatedly, theoretically by Kahneman among others, and in practive through many a crisis, bubble, etc. Arguably "mainstream economics" could be nothing more than a religion, and a very dangerous one by its very high though undeserved power.