AS if last week's stock market roller-coaster was not enough to test the nerve of small investors, some retail clients have complained of getting burned not by plunging prices but by brokers who delayed or failed to execute trades. The consequences could be quite expensive. A source who contacted Family Money on behalf of one investor alleged that a broker's failure to execute a sell order as requested might have cost his client $105,000. 'We have received a number of calls in relation to this kind of complaint,' Securities and Futures Commission (SFC) senior corporate communications manager Chan Chi-keung said. However, such complaints had not 'surged' last week, he said, and the SFC did not get involved in questions of service quality, only those of conduct. According to the source, the investor placed two orders on Monday morning to sell shares of a highly volatile warrant on a basket of red chips at a specified price - the first sell order was for 500,000 shares and the second, placed 45 minutes later, was for an additional 100,000 shares. The client, who was watching the warrant's price with interest, claims the strike price was reached soon after the two orders were placed. However, at the end of the trading day it turned out that only 100,000 shares had been sold. The investor is now in dispute with the broker as to whether this was a partial execution of the initial order or an entire execution of the second. The client has obtained copies of the time-stamped sell orders and maintains the broker simply failed to execute the 500,000-share sale. By Tuesday, the warrant's price had dropped nearly 30 per cent, so a sale at that time would have produced $105,000 less than if the sell order had been executed as requested. This case is by no means unique. Another small investor contacted Family Money last week to complain that it took him more than an hour to get through on his broker's line - and once connected, he was put on hold for a further 15 minutes. In the meantime, stock prices had moved sufficiently to render his planned trade redundant. Patrick Tuohy, senior partner at independent financial adviser Tresidder Tuohy Group, said small investors had long drawn the short straw when it came to brokers' priorities. 'It has been a problem for many a year, though it is possibly accentuated at the moment,' he said. 'No one wants to be in private-client stockbroking any more, there is no money in it.' Even when brokers were willing to act on behalf of individual clients, Mr Tuohy said, they were bound to favour those investing six-figure US-dollar sums rather than individuals investing tens of thousands of Hong Kong dollars. It is not surprising small investors are suffering most. They tend to be the least profitable of clients and, with several daily turnover records set at stock exchange in recent weeks, brokers have been able to pick and choose with whom they deal. Many new smaller investors simply have been turned away. 'Whereas before, you could easily just go to your broker and buy $10,000 to $20,000 of shares, now they are not interested unless you have a cheque for at least $50,000 or $100,000,' one broker said recently. Despite this higher hurdle, the volume of trade handled by smaller brokers - who cater mainly to retail investors - and retail's share of overall stock turnover have shot up. In the 12 months to July, retail investors' trades rose to 61.6 per cent of turnover from 56.7 per cent, according to exchange figures. Meanwhile, category-C brokers saw their business grow almost sevenfold. By June, they accounted for $8.5 billion of the $21.01 billion in average daily turnover. Demand - and past problems with brokers - has persuaded the exchange to launch a series of investment seminars. Last week saw the first in a series on warrants. Investors' rights and obligations are next on the agenda. Henry Law Man-wai, the exchange's director of corporate communications, said investors themselves were the ultimate weapon against unreliable brokers. 'We have more than 500 members in the market. Investors can look for the most suitable one for them,' he said.