While there are some intrinsic differences between bonus issues and rights issues, there are two very interesting similarities. Firstly, a split and bonus result in an increase in the number of shares outstanding and proportionate reduction in the market price. In terms of wealth effect, 1:1 bonus is the same as a 10 for 5 stock-split. Secondly, neither the bonus nor the split will impact your Return on Equity. The split only changes the capital constitution whereas bonus entails shifting money from reserves to share capital; both of which are part of the net worth of the company.