Ronson, whose company Heron International has not had a pure housebuilding arm for the best part of a decade, took a stake somewhere north of 7% last week. Crest's share price duly rose 7.8% to 333p.
Speculation is mounting that Heron will soon make a formal bid. A pal of Ronson told Sharewatch: "Gerald loves housebuilding. It's in his blood."
But one rumour has it that the Crest board doesn't believe Ronson wants to take over; he is simply building a stake in a business that is doing very well, thank you very much.
At the very least, it has added fresh impetus to the never-ending story of consolidation in the sector. One oft-mentioned target, Swan Hill, certainly seems to have benefited.
It hasn't made a significant announcement since May, yet its shares have jumped 12.1% to 88p last week. As one analyst delicately put it: "What the hell is going on with Swan Hill's share price?" But the three most likely buyers did not benefit much. Persimmon rose just 1.3% to 555p; TayWood did a little better with a 3.1% lift to 236p; and Wimpey was up 2.7% to 385.25p.