NEW YORK, May 1 (Reuters) - Blindly following the old Wall Street adage "sell in May and go away" may prove costly, as investors weigh whether to call time on a powerful market recovery heading into a historically turbulent stretch of the year.

The S&P 500 has already staged a dramatic comeback, recovering a near-10% decline in just 11 trading sessions after a selloff triggered by disruptions to global oil supplies. That snapback has left investors asking: is the worst over, or is a seasonal storm still coming?

While the S&P 500 Index's long-term performance for the May-October period, going back to 1945, is a lackluster 2% - well below the nearly 7% gain for the November through April stretch - according to CFRA data, the performance in the last decade has been a more robust 7%, including last year's 22.1% rise.

"You hate to say to ignore 'sell in May, go away' ... but it hasn't worked at all in the last decade," said Ryan Detrick, chief market strategist at Carson Group.

"Investors would really have hurt themselves if they blindly, truly sold in May, went to cash, or even if they went defensive," he said, referring to the market performance over the last 10 years.

WAR, EARNINGS, ECONOMIC RESILIENCE FACTOR IN

Since May 2016, $10,000 invested continuously in the S&P 500 would have grown to about $34,000, nearly double the outcome of a sell-in-May strategy that sat in cash during the summer, a Reuters analysis showed.

This year, several factors offer a rosy picture for equities, arguing against leaning too bearish solely because of the calendar, strategists said.

Stocks have recovered strongly from a sharp selloff as worries about a massive escalation in the U.S.-Iran conflict eased. Strong corporate earnings have bolstered sentiment, and the U.S. economy has shown resilience during the Iran war energy shock.

"If there were ever a year where you might want to throw seasonality out of the window, it might be this one," said Jim Carroll, portfolio manager at Ballast Rock Private Wealth.

MIDTERM YEAR

Sam Stovall, chief investment strategist at CFRA Research, flagged one important consideration that argues for caution about abandoning the sell-in-May strategy: 2026 is a midterm election year, when U.S. voters elect members of Congress.

In five of the last 10 midterm years, the S&P 500 declined May through October, with an average loss of about 1.5%, a Reuters analysis showed.

Also, looming over the outlook is the unresolved U.S.-Iran conflict and its potential drag on global growth.

Investors also have to contend with a new Federal Reserve chair as Kevin Warsh is expected to replace Jerome Powell at a time when analysts expect a bumpier rates path ahead.

"There's certainly an awful lot out there to worry about," Stovall added.

Still, strong market momentum may help stocks overcome these hurdles, strategists said.

Since World War Two, the market has typically climbed more than 8% in the following three months after recovering all that was lost in pullbacks of 5.5% to 9.9%, CFRA data showed.

"Yes, it's a midterm year. Yes, 'sell in May' is coming, but the trend going into this is very important," Detrick said.