Legendary Vanguard Founder Jack Bogle says that the stock market’s gains over the past decade look reasonable — if you trust the accuracy of corporate earnings. And he doesn’t appear to.

“I don’t think that anyone would say the market is cheap,” Bogle recently told Morningstar. “It’s gone up about 65% in the last decade — a pretty good decade, that’s 2004 to 2014– and yet earnings have gone up 85%, even more, and dividends have gone up 100%. So, the fact that it’s way up is supported somewhat by the fundamentals.” But, he says, there may be a fly in the ointment: “It’s that I don’t trust the earnings: Corporations are pressing very, very hard to get higher and higher earnings. They are putting inadequate contributions into their pension plans, and they are pushing the accounts as hard as they can on a whole lot of small issues–and the accountants, not wanting to lose their jobs, comply. I don’t like the system the way it is today. They are taking a lot of out of the hide of their employees.” He says corporations operate with a focus on the short term, when they should be operating with an eye toward the next decade or two.

Bogle also said the recent market volatility is being driven by rampant speculation. “This most recent spate of jumps up and down and around have mostly been speculative in nature,” he said. “Investors aren’t doing anything, I don’t believe, in this market. … And if you don’t believe that, look at the trading volumes. And I particularly look at the whole new speculation in the market … exchange-traded funds. The Standard & Poor’s SPDR, S&P 500 ETF, has in the last week traded $160 billion of its shares, and it’s a $160 billion fund. That’s a 100% turnover in a week, and I guess that means it’s 5,500% or 6,000% in a year, or something like that. That turnover doesn’t do anybody any good, except the people who are doing the trading.” Bogle paraphrased Shakespeare in saying that the short-term market moves are like “a tale told by an idiot: full of sound and fury, signifying nothing.”