Buy after a big share price fall? In this week's Shares we talk 'averaging down', a magic trick of investing or throwing good money after bad. We also ask, 'where next for BT', after its shock £530m Italian write-off, ponder the possibility that markets are already fed-up with Donald Trump, and discover the best deals for investment cash. We discuss why we think Vodafone is a top investment, look for assets to beat the inflation monster and find out how to cut your pension tax. There's also an investment trust that won't stay this cheap for long, plus loads of other interesting features, company news, our best investment ideas, market stats and much more.