Key Takeaways Buffett has long been a big proponent of the index funds that Bogle helped bring to the masses.However, his public declaration that Bogle is an American hero may have also been influenced by the fact that one of Bogle's funds just helped Buffett win a $1 million bet.

No one can know, but here’s how to think about it.

It’s that one decision Buffett says you can’t afford to ignore. Integrity is such a non-negotiable aspect of Warren Buffett’s business practice that he vows the key to success is to associate only with people who possess it. He once said:

With countless funds to choose from, though, it can be challenging to find the right fit. While everyone's situation is different, there's one investment that famed investor Warren Buffett says is the best choice for most people -- and it could help you build a portfolio worth $1 million or more.

TheStreet. Warren Buffett is arguably the most successful investor of all time. He's amassed an amazingly massive net worth by buying and usually holding stocks for the long haul. Trained under legendary value fund investor Benjamin Graham,

Buffett owned UnitedHealth shares before selling his stake in 2010, though his Berkshire Hathaway recently acquired shares.

Leveraged positions in the stock market jumped 18% in one month and topped $1 trillion for the first time. Increasing use of debt to invest can tell us a lot about investors' attitudes. And while this has always been the case,

Warren Buffett warns that while markets reward proactive investors, they are unforgiving toward those lacking knowledge or discipline.