Investors expect Federal Reserve Chairman Ben Bernanke to print more money as the growth rate remains too low, and this is the reason behind the very strong rally in September, Philippe Gijsels, a strategist with BNP Paribas Fortis, told CNBC.com Friday.
Wall Street recorded its best September in 71 years as the Dow Jones Industrial Average rose 773.33 points, or 7.72 percent, its best September result since 1939.
In his recent Federal Open Market Committee comments, Bernanke mentioned three times the risk of deflation, which means that "the bar to once again inject an American football field of money … into the world's largest economy has been substantially lowered," Gijsels wrote in an email.
The second round of quantitative easing is expected to start in November and the combination of weak data and strong expectations that more money will be printed created an "almost perfect" situation for the markets, he explained.
This is because if economic data was strong, they would alleviate fears of a double dip, while if they were weak, they were seen as positive as well because they "brought us one step closer to the football field of money," Gijsels added.
"The whole month of September was like a giant game of heads and tails. Heads the bulls won, tails the bears lost," he said.
But the market is "very overbought now" and some correction is likely to follow, while the question whether a double-dip recession will happen or not will resurface, Gijsels said.
"The amount of effort (zero interest rates and unconventional measures) is unseen in financial history and still the recovery is clearly subpar," he wrote. "Logically this will make for subpar returns as well."
Volatility is likely to dominate the last quarter of the year, as it did in the first three, he said.