1) Never put all my eggs in one basket I.e. Diversify

The logic is here is that. “If you invest in things that do not move in the same direction, at the same time or at the same pace, then you will reduce your chances of losing all of your money at the same time or at the same pace.”

2) Invest only excess funds

Excess funds are the cash that exceeds the cash required for day-to-day operations.

3. Never sell during a down trend (under normal circumstances)

Prices will rebound. "If investors sell when the market is down, they will realize an actual loss. A lesson many investors have learned is that if they sit tight and wait for the upturn to come, they won't realize a loss. In fact, they may even see their portfolios gain more value than they had before the downturn.”