Investors are making the biggest bet in the futures market since 2011 that the stock market is going to sell off.

There’s been a net short position in E-mini S&P 500 futures building since April.

Some strategists believe when a lot of investors take the same position,  there’s a herd mentality at work and investors are actually sending a contrarian signal. In this case, that would be positive for stock market gains. But Peter Boockvar, chief investment strategist at Bleakley Advisory Group, disagrees that stock futures investors are necessarily representing a contrarian call.

According to the CFTC, as of last week, there was a net short position of 303,000 futures contracts for the S&P E-minis held by the noncommercial traders, an investment group viewed as speculators. In early March, the same investors held a net positive position, at a high of about 55,000 contracts.

Boockvar said about twice as many futures contracts were now short as long, for the week ended last Tuesday. He points to cases where the shorts were right, like in September 2007 when they were at a record high ahead of the market peak in October.

He said there were record high longs in March 2009, another trade that turned out to be right as the long bull market began that month.

“They were right. I’m skeptical to look at this as a contrarian indicator. I’m going to argue that sometimes the shorts are right,” he said. 

Boockvar said he doesn’t actually know what to make of the positioning. It’s more cut and dry in the case of commodities futures, like corn or oil, where the producer is on the other side of the trade.

“CFTC data should be looked at as a contrarian indicator, but I don’t believe that’s with the S&P 500 futures. You could have people long stocks and hedging with futures. That doesn’t mean they’re net short,” he said.