Summer getaways latest casualty on Wall St.

NEW YORK (CNNMoney.com) -- July and August tend to be sleepy months on Wall Street as traders ditch their terminals and head for a beach house in the Hamptons or a summer resort on Nantucket.

But with the market in turmoil and no end in sight for the credit crisis this summer, Wall Street pros have been awfully busy lately, getting some not-so-subtle hints that they may want to rethink their dog-day getaway.

"Is it mandated? No. Is it discouraged? Absolutely," said Jim Herrick, head trader at the Milwaukee-based investment firm Robert W. Baird.

In some instances, traders have been taking the initiative themselves.

"I've heard that people are canceling vacations," said Joseph Saluzzi, co-head of equity trading at Themis Trading. "They want to be around in case something goes wrong."

Some people have been called back from vacation. One manager of high-yield corporate loans had to come back from the Berkshires for two days until the credit markets started to steady. But that was weeks ago.

Other financial institutions, including some of Wall Street's biggest investment houses, said it was business as usual.

Bond trading firm PIMCO has not had to order any employees back to the office, saying, "We have been prepared for this for quite some time," a company spokesman said in an e-mail to CNNMoney.com.

Investment management firm BlackRock reported that some employees are having to put in some time during their vacation, staying in contact with the office.

Global markets have been on a rollercoaster ride in recent weeks as uncertainty about recent credit market woes unnerved investors, who were scrambling to safeguard their positions one day, then often bargain-hunting the next.

Maybe the best gauge of how busy it has been on Wall Street this summer is the number of shares that have changed hands in recent weeks. Typically average volume drops off between Memorial Day and Labor Day.

But in just the last three weeks, the New York Stock Exchange posted its five biggest trading days of all time, measured by shares traded.

"This would be an anomaly," said Jeffrey Hirsch, editor of the Stock Trader's Almanac, noting part of the record volume is from firms unwinding positions as the markets have gyrated.

Right now, no one can give a definite answer as to when trading might revert to more normal levels, though some have speculated it might not be until October when corporations, start reporting third-quarter results.

Even then stocks could be in for more tough sledding if profits get hit by the fallout from the meltdown in the subprime mortgage market and the resulting credit crisis.

But in an era when computer-driven hedge funds and Blackberrys are the norm, leaving the office may not have the crippling effect on a trading desk as it might have had in years past.

"I'm taking next week off," said Michael Schwartz, chief options strategist at Oppenheimer & Co. "With a cell phone, a trader can be on vacation but not far away."