THE kids on the block in Queens where William Casey grew up called him Cyclone because his angular body seemed to be constantly in motion. The nickname still fits Casey, who is now chairman of the Securities and Exchange Commission. His seven months in office have been filled with a bustle that the agency had seldom known in its first 37 years.
Under Casey's guidance, the SEC has moved briskly to enforce negotiated brokerage-commission rates on stock trades of more than $500,000, order stricter capital requirements for securities firms, tighten up corporate bookkeeping and require all companies whose stock is bought by...