(Bloomberg) -- Skepticism is one thing this stock market rally hasn't lacked. You just have to look for it.

The Nasdaq is setting records while the S&P 500 hovers near an all-time high. Betting against the market when it's putting up these kinds of numbers can be a sucker's game, and not surprisingly the biggest ETF tracking the S&P 500 has seen bearish bets plummet to their lowest level in 10 years.

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