by charts and patterns and high end mathematics. if you are not sure please toss a coin and
draw a graph thease patterns will be available. in short term market is very random. if you trade only trade by proven fact with significant impact that still know one have a clue. other wise you will end by bankrupted using stupid charts and engineering mathematics in the market. if you want to be successful do long term trading. now dont ask what is long term
long term is 30+ years. buy when evryone tells that this is the end of world.sell when fundamentals are deteriorated due to high price levels which seems no real sence of that high price