According to BTIG Researchscratch3.2Before the bulls take full control of the stock market, pessimistic investors basically have only one key level left to defend.

Jonathan Krinsky, chief market technical analyst at BTIG, said U.S. stock bulls were "clearly controlling the market" and the S & P 500 was above its downtrend and 50-day moving average.

He said that there is only one number left for short sellers to remain below the market indexscratch3.2: 76% of the S & P 500's recent declinescratch3.2.4% retracement level, in which case the S & P index will be around 5191.

"Obviously bulls are thriving in this market," Krinsky said.