On balance the negative tone in Wall Street’s technology sector is probably justified because all the signs are that the US market for computers, not at its brightest for a couple of years, looks as if it is if anything getting soggier – and companies that do have full order books are constrained by the semiconductor shortage: the problem created by the latter factor is that these imbalances seldom work out of the system cleanly, and history suggests that supply and demand for memory chips will come into balance just as the market goes decisively ex-growth, leaving manufacturers with big stock surpluses.