A gorilla named Jacko has failed to beat the Dutch blue chip index for just the second time in the 15 years he has been picking stocks, website Beursgorilla.nl said on Tuesday.

By December 30, Jacko’s portfolio had fallen 7.26% on its value at the start of the year, compared with a rise of almost 6% on the AEX itself.

Jacko’s losses are due to technical services group Imtech, which he ‘bought’ for nearly €29,000 last November. Those shares are now worth just €78.33.

The Beursgorilla campaign began in 2000 when a gorilla was asked to pick 10 bananas from a selection representing all AEX, midkap and smallkap index shares. Since then, Jacko has been allowed to swap stock each month.

Since the experiment began the gorilla has beaten the AEX 13 times and booked an average annual return of 4.5% a year. The AEX, by contrast, has gone down by an average 3%. Jacko’s portfolio which began at €100,000 is now ‘worth’ €208,000.

The Beursgorilla website says the aim of the Jacko experiment is to warn investors against unrealistic expectations and promises from investment funds.