Investors have a serious case of Icahn fatigue

Activist investor Carl Icahn has yet again had a go at pumping up the value of Apple stock.

Icahn has become fond of Twitter as a platform, but 66 messages in and the attention of market watchers has started to wear thin.

Three consecutive updates failed to make much of a dent in the value of Apple shares.

When Icahn first tweeted about the tech giant last August, the share movement was much more pronounced.

While giving far fewer specifics and far fewer characters to the issue, Icahn's first comments added $17bn (£10.3bn) to the value of Apple's stock, with shares closing 4.75 per cent higher that day.

The jump left the shares at $489.57 in August, their highest level since January. Today's comments have seen Apple shares tick slightly higher, from just under $554 to a fraction above $556.

More frequent updates are having less significant effects.

When once Icahn could push the value of the stock up by over $20, now he's only been able to see shares up by about $2.