There is no doubt that July and August will be remembered not for the hot summer weather but for turbulence in the global stock markets.

As a result, what better time to start the fifth Rehab Great Investment Race than right in the middle of the volatility, enabling the stock-picking skills of some of Ireland's top fund managers to be tested to the full.

Their challenge over the next 12 months is to grow the €100,000 they have been given by Rehab Lotteries, with any profits made going to help autistic children and their families in Ireland.

With the Iseq Index of Irish shares losing 7 per cent in the six weeks to the end of August, the FTSE dropping 6.4 per cent and the Dow Jones Industrial Average shedding 3.5 per cent, the task will not be an easy one, but it seems that last year's winners, Oppenheim Investment Managers, are on a mission to prove that they can do it two years in a row.

Under the guidance of Stephen Hynes, Oppenheim ended the first leg of the race at the top of the leaderboard, with a gain of 7.3 per cent, equating to a profit of €7,277.

After holding on to cash for the first part of the period as a result of the shaky market conditions, Hynes left off where Oppenheim finished the last race, with some very active trading. During the period he bought 19 stocks and sold 15.

"It worked for us last time, so we didn't see any reason to change," he says, adding that while he will trade the fund actively where he sees value, he won't be trading for the sake of it.

Hynes said that the majority of the stocks were held only for a few days and were bought and sold largely on technical factors and where they looked oversold. Irish bank Anglo netted the group a decent gain, as did Apple Computer, which gained on the back of the new iPhone.

He said that in the future he would have no qualms holding some or even all of the fund in cash if markets looked particularly shaky.

Meanwhile, Seamus Magner at Irish Life Investment Managers was also doing something right with his stock-picking as his €100,000 grew by 3.4 per cent, to end the period at €103,430.

Unlike some of the other participants in the race, but in line with the approach taken by Oppenheim, Magner also traded very actively during the period, buying 12 stocks and selling 11. His trades included Ireland's CRH and several banks such as Anglo, Depfa and ABN Amro. At the end of the period he was holding only mining group Zambia Copper.

One of Magner's best bets during the period was Anglo. He bought 2,000 units at the end of July, only to sell them the following day, making a profit of more than €1 per unit.

Magner also made significant gains trading in Northern Rock, the UK bank whose shares declined significantly amid concerns over the deteriorating credit markets only to be boosted in the other direction as a result of bid talk.

AIB Investment Managers came in in third position, with a gain of 2.1 per cent, bringing the fund's total value to €102,097.

Tom Bargary, the fund's manager, had a quiet six weeks, holding on to all the stocks he bought and finishing the period as he started it.

His holding includes Australian mining group Rio Tinto; UK technology providers SAP; Japanese gaming group Nintendo; Electronic Arts, a US video games group; and National Oilwell, a Texas-based manufacturer of oil-drilling equipment.

Elsewhere, Noel O'Halloran, manager of KBC Asset Managers's race fund, expressed satisfaction at the group's performance, despite recording a loss of 0.4 per cent for the period.

"It was a relatively short period and the markets were very volatile," he said, adding that he was quite happy with the fundamentals of the five stocks he chose at the start of the race and saw no reason to sell any of them during the period.

This does not mean, however, that he will hold on to the same stocks throughout the whole competition, as Bank of Ireland Asset Managers did with Pfizer in the fourth race.

Instead, O'Halloran envisages holding between three and seven stocks in his portfolio across a diverse range of themes and sectors, and selling them when they no longer merit being part of the fund.

His fund currently contains Irish building materials group CRH; Smartrac, a Dutch technology group; Acciona, a Spanish renewable energy company; Brazilian technology group Tele Norte Leste Participacoes; and Cia de Saneamento Basico, a water treatment group based in Brazil.

Finally, bringing up the rear with a loss of 3.7 per cent, or €3,683 for the period, is Bank of Ireland Asset Managers.

Pat Cunningham, heading up the fund, also held on to the four stocks he chose at the beginning of the race because they looked good value on a 12-month basis. He said that after six weeks they still looked good value and as a result he saw no reason to sell them.

His holding includes Vallourec, a French services company which makes metal pipes; steel giant Arcelor Mittal; UK bank Northern Rock and Hong Kong property developer Sun Hung Kai Properties.