Activist investor Sandon Capital has sought to counter concerns about more client money leaving Magellan since the departure of its veteran infrastructure portfolio manager Gerald Stack was made public last week.

Magellan shares fell 23.5 per cent in the three days since the global equities manager informed the market of his exit. But equally, the sharemarket is not adequately valuing Magellan’s stake in investment bank Barrenjoey, said Sandon’s chief investment officer Gabriel Radzyminski.