They way I do this (in the UK using ISA's and mostly Investment Trust based) is when an individual stock gets to big relative is to stop reinvesting dividends

They way I do this (in the UK using ISA's and mostly Investment Trust based) is when an individual stock gets to big relative is to stop reinvesting dividends in that stock and reinvest that dividend in other's. At the moment I just invest once a month combining last months savings with accrued dividends - which rebalances a little. For example I have stopped reinvesting in Witan, Lowland and TR Property - in favor of smaller holdings - which at the moment looks like this. BANKERS INV TRUST ORD GBP0.25 CQS NEW CITY HIGH ORD NPV BT GROUP ORD GBP0.05 LAW DEBENTURE CORP ORD GBP0.05 JPMORGAN EMER MKTS ORD GBP0.25 POLAR CAP TECH TST GBP0.25 SCHRODER ORIENTAL ORD GBP0.01 CITY OF LONDON INV ORD GBP0.25