People lose money in the markets because they let emotions mainly fear and greed drive their investing.

This study of the influence of psychology on the behaviour of investors or financial analysts is actually known as behavioural finance.

Behavioural finance is the marriage of behavioural psychology and behavioural economics explains why investors make poor decisions.

For example, following the herd mentality is one of the worst behavioural mistakes you can make. It plays out whenever you blindly go where most others are going.

Some people lose money in the markets because they think investing is a get-rich-quick scheme. You can quickly lose your investment dollars by employing penny stock or day-trading strategies.

An investor who exhibits herd instinct generally gravitates toward the same or similar investments as others. Herd instinct at scale can create asset bubbles or market crashes via panic buying and panic selling.
To avoid losing money in the markets, You have to tune out any promise of quick riches.

Like the Tortoise and the Hare, a “slow and steady” strategy will win the race. What are your views on this?