> Each stock fraud is fraudulent in its own way. But there are common elements. One is a breach between earnings as defined by Generally Accepted Accounting Principles (GAAP) and non-GAAP measures. Another is an increase in “days payable outstanding”, a yardstick of how long it takes a company to settle bills with suppliers. Delay boosts cashflow, at least for a while. So does gathering more quickly payments you are owed. Firms with dressed-up earnings also tend to pile on debt because they lack strong underlying cashflow. And there are grounds to suspect the worst of companies that engage in a lot of acquisitions. Aligning the accounts of acquirer and acquired gives ample scope for fiddling.

> Transcripts of conference calls with stock analysts can also be revealing. If the company keeps moving the goalposts, then be on alert.