But the rise did not stop there. The rumour grew legs and sprinted off like Ben Johnson on steroids, lifting shares a further 12p to 253.5p by the time the market had closed on Monday.
Rather boringly, the name of usual suspect Persimmon has been floated as a potential buyer this week, with the acquisition-hungry company's share price up 11p on Monday to 486.5p. This was probably something of a relief as it had fallen 1.5% last week to 475.5p.
After rumour-driven boosts, it was good to see that support services groups Interserve and White Young Green benefited for rather more tangible reasons. Both issued trading statements last week. Interserve announced that it would sell-off some of its loss-making operations, resulting in a 7.6% increase last week to 254.5p.
White Young Green's statement that its order book is 23% higher on the same time last year at £125m moved its shares 3.3% to 158.5p.