When you set a target % for a company in your share portfolio you get a message saying automated buy and sell orders will be generated automatically. How does this automatic ordering work?
You just sit back, and in a few days, as long as there is demand for the shares that you're selling, and supply for the shares you're buying, you'll hit your targets. Careful about doing IPO's, once you get to your targets. IPO's and PO's create new shares.