AFTER choosing a stock the next decision is to find the right stockbroker to handle the trades. For the first-time buyer, this can be a difficult choice. The best advice is to ring around to find out who appears to be the most competitive and accessible. Also, check the broker is authorised by the Securities and Futures Commission, the territory's chief financial watchdog. The number of shares an individual might buy depends on personal preference and the rate of subscription for the launch. A broker expecting a new issue to be oversubscribed will generally recommend the investor submit extra subscription forms. For example, if an investor wants 10,000 shares and the broker expects a stock to be oversubscribed 10 times, then the investor might subscribe for 100,000 shares. Usually, the investor will receive a proportional number of shares depending on the rate of over-subscription. Most retail investors borrow money from the broker to purchase new issues. Called 'buying on the margin', investors generally must put down 10 to 20 per cent of the funds they wish to invest. Borrowers must pay interest on this amount - essentially a short-term loan - to the brokerage house, which generally charges the prime rate plus between one and three per cent. For the retail investor, this means the effective price per share increases substantially. In the case of Ng Fung Hong, investors who bought at $3.20 on the margin essentially paid $3.50 to $3.70 per share. The broker submits to the underwriter subscription forms which should be returned within seven to nine days. After that, there is nothing for the retail investor to do but wait until trading begins.