How does "big loss" occur?

Typical scenario:

In a market downturn, traders continuously buy based on various "reasons":

"There is a support level at a previous low" → Place limit order.

"It has reached a certain moving average" → Market buy.

"Indicators are oversold/diverging" → Market buy.

"Important round number"→ Place limit order "give it a shot".

Result: Either increase positions all the way leading to a final big loss,

or frequently "stop loss - buy again - stop loss" losing a large amount of funds in a short time.

Essence: This behavior is exploratory trading based on feelings and without rules, relying on "luck" rather than "probability advantage".