Ericsson (ERIC)  shares traded at the highest level of the year Wednesday as investors reacted to Cevian Capital's new stake in the Swedish telecom equipment maker.

Cevian Capital has built a 5.6% stake in Ericsson, according to a Tuesday regulatory filing, and has said that it wants to play an active role in implementing the strategy of new CEO Borje Ekholm. Cevian joins Industrivarden and Investor AB among the ranks of Ericsson's top owners, according to FactSet data.

Ericsson stock rose more than 4.7% in the opening hour of trading in Stockholm to change hands at Skr63.30, a year-to-date high, before paring gains, which was in contrast to the 0.03% loss of the Stoxx Europe 600 Telecommunications index.

The Swedish firm parted company with its former CEO Hans Vestberg in July after an 18 month long period of underperformance, in which sales fell, costs rose and earnings left investors consistently disappointed.

Ericsson was also embroiled in corruption investigations across a number of jurisdictions. Vestberg was widely reported at the time to have been a casualty of Industrivarden and Investor AB's making.

The company has since doubled-down on its efforts to cut costs and focus on its core business, which spans networks services, digital services and the internet of things.

At the heart of Ericsson's decline was a deterioration in competitiveness, in terms of networks and hardware, when it was stood next to China's Huawei Technologies and Finland's Nokia (NOK) .

Given this, and the above commentary from analysts, it is possible that some investors might require more than a "core business and cost cutting" narrative to keep them interested in the company.

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