you are to understand that those whose businesses fold up did try hard enough, and those who ended up investing in a bad portfolio did do their thorough research. This means everything worth pursuing whether it's starting a business or investing in the stock market has a 100% odd of succeeding or failing. Luck is what happens when it succeeds and risk is what happens when it doesn't.

A lot of people would detest you attributing their accomplishment to luck especially when they find they had worked hard to get there. And then some people will rather be blamed for not doing proper research before investing when they lose their money in the stock market instead of attributing these scenarios with risk.

 if you acknowledge that luck brought you success then you have to believe in luck's cousin, risk, which can turn your story around just as quickly'