IBM Corp shares took a tumble, off $1.375 at $86.125 after Soundview Financial Group’s Steve Cohen slashed his profit forecast for the quarter and year, suggesting just 25 cents a share for the first quarter and a very moderate $4.50 for the year where he had been going for 90 cents and $6.50; he also cut his 1993 estimate to just $5.75 a share from $7.75: the mean estimate of 19 analysts for the first quarter is 96 cents a share, three cents better than the year ago figure, Dow Jones reports; Cohen cites weakness in all of IBM’s businesses apart from Summit, the rise in the value of the dollar, and the likelihood of yet more cost-cutting.