The best six months for stocks is about to begin, predicts MarketWatch columnist Mark Hulbert.

He bases his prediction on “the Halloween Indicator,” or the stock market’s seasonal tendency to produce its best returns between Halloween and May Day, commonly referred to in market lingo as the “winter” months.

This tendency is also called “Sell in May and Go Away,” since those who mechanically follow it go to cash during the “summer” months (from May Day until the subsequent Halloween), Hulbert writes for MarketWatch.com.

“Over the seasonally-favorable six-month period that began on Halloween 2014, the Dow gained 2.6% — versus a loss of 2.6% in the unfavorable summer months that began last May Day,” he said.

This seasonal tendency has been stronger over the last 15 years than it was before, he explained.

And “these already-impressive statistical odds become even better when the stock market is able to buck the seasonal odds and eke out a gain over the September-October period — the last two months of the seasonally unfavorable summer period. That’s exactly what’s happened this year, with the Dow currently 5% higher than where it stood at the end of August,” he said.

But he did caution that the indicator isn’t foolproof.

“Note carefully that the Halloween Indicator doesn’t guarantee that a bear market won’t occur. But if the future is like the past, the worst of any upcoming bear market will wait until after May Day of 2016 — since the bulk of market damage during past bear markets has occurred during the summer months,” he said.

Meanwhile, other financial experts are joining Hulbert is seeing additional gains for the U.S. stock market in the near future.

Leon Cooperman and Steven Einhorn's Omega Advisors told investors the bull market in U.S. shares was intact and that equities should generate a mid-to-high single-digit annual total return despite August's market turmoil.

In a letter to investors dated Oct. 17 and seen by Reuters, Cooperman and Einhorn said it would take time to restore investor confidence in U.S. shares after the volatility and forced selling that drove stocks down 10 percent over five sessions near the end of August.

Omega said investor sentiment should improve if the market sees stability in Chinese economic data and in oil and commodity prices, a narrowing in corporate and high-yield spreads, clarity by the Federal Reserve on interest rates, rising U.S. Treasury yields and increased quantitative easing from the European Central Bank and Bank of Japan.

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