Disk drive manufacturer Quantum Corp plans to spend $28m or so buying up to 2m of its 10.2m shares outstanding, in a Dutch auction in which it will start at $14.75 a share for the lucky few who get their bids in quick, going progressively down to $13.25 a share until it has all it wants: the company says it is buying because it reckons that at current prices its own shares represent a good investment.