The S&P 500 Index is officially at a loss year-to-date (YTD), closing down 3.1% on Wednesday as U.S. equities continue their free fall.

Now, one market watcher is forecasting another up to 10% dip for stocks before the market hits a bottom, as outlined by CNBC

Sell-Off Will Take 14 to 16 Weeks to Work Itself Out

Just months after setting all-time records, the blue chip S&P 500 is sinking on a handful of concerns including heightened global trade tensions, rising interest rates, lackluster earnings, and mounting regulatory pressure on once high-flying tech giants. Over 70% of the index's components are currently in a correction or worse, defined as a 10% or more dip from a 52-week high. Beaten down stocks across industries have fallen deep into a bear market, including food industry company Kraft Heinz Co. (KHC), auto industry titan Ford Motor Co. (F) and chip player Advanced Micro Devices Inc. (AMD). 

In an interview with CNBC's Trading Nation on Tuesday, Piper Jaffray chief market technician Craift Johnson indicated that the worst is yet to come for U.S. equities. 

"We had this kind of fake-out/breakout scenario. It's ended up becoming a fake-out similar to what we had seen in 2000 and 2007 and now we're coming back down to retest support at 2,700," said the analyst. 

Before Tuesday, the S&P 500 had not fallen below to 2,700 mark since late June. In February's sell-off, the index sank to 2,532, and on Wednesday it closed at 2,656. 

"Usually when we get to this kind of weak internal readings we end up seeing some sort of flush-out. I think that flush-out is still ahead. I think it's going to be another 5 to 10 percent lower from here and it's probably going to take about 14 to 16 weeks to work out itself out," stated the Piper Jaffray technician. 

Moving forward, Johnson sees an "investable bottom" for the S&P 500 near the "long-term uptrend support line" at around 2,500. "It probably is going to be a little bit longer before we get there," he added. 

Susquehanna market strategist Stacey Gilbert chimed in on the CNBC segment with a cautious outlook for the market, noting that her "biggest concern for the market right now is not what's known, it's the potential gap risk that's out there. If we do go down, I am worried that the down drop is significantly larger than obviously... what we would see on an upturn."