The cost of buying and selling
Trading, timing and stock-picking all promise an edge. Costs and cycles usually take it back
Investors like to believe that skill can be separated from cost. It cannot. Every strategy that involves moving in and out of markets carries a cost of the trade and the associated tax when profit. Three approaches to beating an index — technical trading, valuation — based timing and stock-picking — illustrate the point rather well, and each fails, or succeeds, for a different reason.
Source: https://www.magnific.com/


