Passage Summary: Most people who play the stock market don't do their homework, relying instead on brokers or vibes, but most of them still manage to turn a profit.

Reasoning: Most investors skip personal research in favor of brokers or gut feelings, and even those who do research often fall back on those same sources, yet most still end up making money.

Analysis: Since we are told that a majority of investors make a profit, but only a 'few' always do their own research, there is a mathematical overlap we cannot ignore. You should look for an answer that reflects the fact that some people are making money despite not doing their own research. In 'Must be True' questions, we aren't looking for why this is happening—maybe they're lucky or their brokers are geniuses—we are simply looking for what is logically guaranteed by the numbers provided.