...crucially, fundamental outlooks–for earnings, interest rates, credit, investment, employment, and whatever else is relevant to the asset class or security in question–move in trends. An important example would be the business cycle. The economy sees an expansionary period of rising investment, employment, output, profits, wages, optimism, and so on. Imbalances inevitably accumulate in the process. The imbalances unwind in the form of a recession, a temporary period of contraction in the variables that were previously expanding...
The fundamental outlooks of investors influence their assessment of the fundamental value that is present in markets, and also dictate their expectations of what will happen in markets going forward. These impacts, in turn, influence what investors choose to do in markets–whether they choose to buy or sell. Buying and selling determine prices. So we have the basic answer to our question. Market prices trend because the fundamentals they track trend, or more precisely, because the fundamental outlooks that guide the buying and selling behaviors of their participants trend....
www.philosophicaleconomics.com/2015/10/trend/
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