It is not only consumers who are reducing their debts. The latest Reserve Bank data on margin lending, released yesterday, show that investors are also deleveraging.Total margin loan balances fell 12 per cent in the September quarter - down from A$18.1 billion at the end of June to $15.9 billion three months later.Over the year to September loan balances fell 18.8 per cent.The big margin lenders are Commonwealth Bank, Westpac and Leveraged Equities, owned by Bendigo and Adelaide Bank.From a peak of $41.6 billion, in December 2007, the margin lending market fell to a low of $20.6 billion in June 2009. The market staged a weak recovery in the second half of 2009 and 2010, but the latest period of volatility on the equity markets has put paid to that.The number of investors operating margin loan accounts has seen a more modest contraction. From a peak of 248,000, in December 2007, accounts numbers have fallen 12.9 per cent to the current level of 216,000. The average number of margin calls per 1000 account-holders per day rose from one in the June quarter to 1.8 in the September quarter.In the depths of the 2007/08 bear market the number of margin calls reached 8.6 per 1000 account-holders per day.