The key distinction is that, whereas the speculator takes a view based on the price which he observes in the market and acts upon it, the manipulator uses his resources and the advantage of a dominant market position to try to influence the price - in other words, he is a potential price setter rather than a price taker. Particularly in small markets where relatively small deals may be able to move prices significantly, we need to be alert to this potential problem, which may, if unattended, seriously undermine one's vision of competitive, efficient markets. Information The prices at which derivatives trade contain information which may usefully supplement other market data available to central banks as a means of monitoring expectations and sentiment. Let me give just two examples. First, in the foreign exchange market, whereas the forward rate may provide a point estimate of the expected future rate, data on option prices for different strike prices can provide a probability distribution for the future rate. This additional information, available only as a byproduct of derivatives trading, may be of interest to market analysts, including the monetary authorities. Within the HKMA we have conducted some research into this, which we are in the process of discussing with academics and other technicians. Second, with exchange traded products, where levels of activity are clearly visible, sudden surges or collapses in turnover may hint at shifts in sentiment for one reason or another.
This is perhaps a rather dry topic and I feel sure that there are many more interesting and challenging aspects of derivatives which will be discussed during these two days of seminars related to the Derivatives Expo. 2  Record of discussion of the Exchange Fund Advisory Committee Sub-committee on Currency Board Operations on 5 November 1999, reproduced in HKMA Quarterly Bulletin, February 2000. BIS Review 91/2001  3