The has staged an impressive rebound from its memorable mid-February low of 1,810, but the market is about to give back all of those gains and then some, according to investment strategist Larry McDonald.
"We're going to have a very, very tough run in the next six months," McDonald, global head of macro strategy at ACG Analytics and formerly Societe Generale, predicted Thursday on CNBC's "Trading Nation."
As McDonald sees it, the market is essentially in a lose-lose position going into the June Federal Reserve meeting, out of which some expect the central bank to announce a second rate rise.
"If they try to hike in June, the dollar's going to rip, oil's going to get slammed, emerging markets are going to get slammed and once again we're going to go risk-off," he said.
If, on the other hand, the Fed doesn't increase rates, "then bad assets, bad loans, more ugly credit formation keeps building. And either way," stocks are set to drop.
Just how far will equities fall?
"I think we're going to break 1,700," and get to "1,670 on the S&P before the end of the year or before first quarter next year," which would be a 20 percent decline from Friday's opening price, he said.
Only time, of course, can tell whether this prediction will come true.
If it does, "that would be a very attractive buy," Eddy Elfenbein of the Crossing Wall Street blog said Thursday, adding, "But I wouldn't be waiting to get to that level."