"follow the trend" is usually a good idea, shorting when the trend is up is pretty risky, but then again so is buying a stock for FOMO. Generally when u read about a stock making people millionaires its time to sell, when u see elon musk smoking joints and everybody fears tesla will go down then its time to buy...It's probably best to do the opposite of what everybody else does. because its always the smaller group that gets rich and the bigger group missing out.
