1.   The interpersonal exchanges in speech have other important advantages for the learner.

2.   But to achieve these advantages, derivatives exchanges have had to devise institutional arrangements to ensure the absence of default risk.

3.   Other exchanges have to rely on niches that are impervious to the competition from the low cost exchange -- they compete by innovating such niches.

4.   How much actual, constructive or imputed knowledge does an exchange have of what goes on on its own trading floor?

5.   In return for meeting these standards the exchange has insulation from liability for negligence to specific persons.

6.   Nevertheless, every exchange has its illiquid contracts, and from a regulatory point of view, liquidity is not essential.

7.   The exchange has a continuing obligation to monitor markets and to identify and address potential abuses.