“Buy when there’s blood on the streets” – Baron Rothschild; Simply explained, buy when the market crashes as it’s drowning in red (‘blood’) numbers.
“Buy the rumors, sell the news”. Buy when a certain rumor is published in the news, about for example a cooperation or take-over between companies, which creates interest and hype and sell when just before or when the official statement is spread out in the news.
“Buy when there’s fear, sell when there is hype”. Sums up the upper two. Buy when traders are trying to get rid of their investment, because of an incoming uncertainty. For example a pandemic, war or just a rumor about a company going bankrupt. When the sky clears up and everything is going back to normal sell your investment to gain profit from the fearful situation.
The phrases sounds simple, but keep in mind that it takes good sources, practice, experience and controllable emotions to anticipate on those situations. And never invest more than you can afford!