Bendigo and Adelaide Bank has largely maintained its market share in the much diminished business of margin lending (or lending to fund investments in shares).The bank's margin lending book is down to A$2.3 billion at June 2012, less than half the level of the peak value of this business.There is "not a lot we can do about margin lending," Mike Hirst, the bank's CEO, said yesterday.Richard Fennell, the bank's CFO, said: "We tend to go into each year with an expectation that following the pre-paid campaign that the rest of business will stay reasonably flat. "As has been shown over the last couple of years, that expectation's been pretty way off."