Stock market correction by October: Strategist

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The U.S. stock market will drop by 10 percent at some point during the next five months, pulling the S&P 500 lower to 1,900, Stifel strategist Barry Bannister wrote in a note to clients.

"We believe the S&P 500 has reached the end of the road in terms of being supported by the trilogy of weak commodities, dollar strength and a low 10(-year) yield," Bannister said in Monday's note.

The other big factor is the end of the Federal Reserve's stimulus. His report showed a high correlation between the rise in the S&P 500 and the expansion of the Fed's balance sheet since 2009.

The central bank's assets have leveled since it halted the purchase of Treasurys (QE) last October, yet the S&P 500 has continued higher.

Stocks will correct during "the seasonally weak May-October 2015 period due to the weight of a Fed Assets-dependent S&P 500 pricing model we use," Bannister wrote.

In other words, without the Fed's free money, stocks are worth a lot less.

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The report's other big call is that oil prices will surge as the dollar falls, a move that will help trigger the stock correction.

The call for a correction is a reversal of a bullish call the strategist made about U.S. stock market last October after an end of the Fed's quantitative easing caused the S&P 500 to drop almost 10 percent.

Bannister predicted the S&P 500 would rally to a record 2,300 level in a "reasonable" amount of time. He got the direction right, but was a little too bullish as the S&P 500 hit a record price just above 2,100 last month.