Flipper, charing works ( with a high probability) is because most of the trading is done by computer algorithms that follow certain technical indicators such as moving averages ( short and long term), patterns, stochastic , volumes etc. We watch for these but because we're just retail and amateur traders we are no match for the computer in terms of processing power and speed, yet we can see the patterns that work well for the intermediate term and this comes with experience. There is nothing difficult if you have time to study it. These patterns recur in all securities hence you can use it to trade or invest ( find good entry and exit spots.)