Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

Is it true that 90% of investors lose their money?
For some studies on why investors make the decisions they do, check out  For a more readable, though less rigorous, look at it, also consider Kahneman's recent book, "Thinking, Fast and Slow", which includes the two companion papers written with Tversky on prospect theory. In certain segments (mostly trading) of the investing industry, it is true that something like 90% of investors lose money. But only in certain narrow segments (and most folks would rightly want traders to be counted as a separate beast than an 'investor').  In most segments, it's not true that most investors lose money, but it still is true that most investors exhibit consistent biases that allow for mispricing. I think that understanding the heuristics and biases approach to economics is critical, both because it helps you understand why there are inefficiencies, and also because it helps you understand that quantitative, principled investing is not voodoo black magic; it's simply applying mathematics for the normative part and experimental observations for the descriptive part to yield a business strategy, much like any other way of making money.