CNBC's Jim Cramer knows that sentiment matters when stocks are constantly being driven higher by a raging bull market.
But the "Mad Money" host also knows that sentiment is extremely difficult to measure. So Cramer has started asking people why they don't like the market. So far, he's been met with a cacophony of eye-opening answers.
One major reason Cramer has heard is that people can't afford to invest in the stock market, despite Cramer's advice to start with small investments and build on their gains.
Often times, Cramer asks if they like their iPhones. When they say they do, he asks why they wouldn't go buy shares of Apple.
"They typically screw up their faces and say, 'I don't know. I have no idea.' Well, let me tell you something. The company that is Apple reported tonight and it was one of the greatest blowouts I have ever seen," Cramer said. "Spectacular revenue growth, amazing earnings, a re-acceleration in China, bountiful services stream, and you just try getting an [iPhone] 10. Just try."
"No one got Apple right except for us," he said. "What a shame, as this company, with a market cap approaching what could be $1 trillion, could have made fortunes for people if they would just understand that you can own — not trade, but own — a piece of this amazing company."