Warren Buffet, the so-called Sage of Omaha, America’s second richest man and stock market legend, gave some of the globe’s leading agency holding companies a much-needed shot of adrenalin over the weekend - and again Monday.

Buffet, whose Berkshire Hathaway investment vehicle is headquartered in the financial boondocks of Omaha (hence the soubriquet) last Thursday revealed his company had bought 500,000 share in Omnicom Group, valued at the time of purchase at nearly $28 million (€27.74m; £17.70m).

The knock-on effect immediately benefited other agency players, especially the UK-based trio WPP Group, Aegis Group and Cordiant Communications – all of whose shares rose sharply on Friday.

WPP gained 5.7% to £4.55 with the momentum sustained through to Monday’s close when its stock stood at £4.80; Aegis fared similarly, up 5% Friday to £0.76 and to £0.7875 on Monday. Cordiant rose 3% to £0.44 but fell again Monday to £0.42.

Havas, Publicis Group and - unsurprisingly - Interpublic Group were seemingly unaffected by the Omaha phenomenom.

Data sourced from: AdAgeGlobal.com; additional content by WARC staff