The rise of the FTSE 100 to its highest level of the year has been driven by small investors trading in shares at levels not seen since the "dotcom" boom. Figures show the number of deals placed through retail stockbrokers climbed to more than four million in the three months to June, a figure beaten only in the spring of 2000. Brokers said low interest rates on savings accounts and scepticism about the property market have forced investors to look to equities in the hope of riding a six-month