The FTSE 100 index, the barometer of corporate Britain’s well-being, has been in rude health and hit a 4½-year high last week, buoyed by takeover frenzy. Profit-taking saw the Footsie ease 44.6 points to 5,764 on Friday, but there is confidence that the index can return to levels above 8,000. Finspreads, the betting firm, is offering a year-end contract spread of 5,803-5,819.