Activist investor Elliott Management has built a near 5% stake in BP and is pushing the oil company to take radical action to transform its performance, including a big divestment programme, a source familiar with the matter told Reuters on Thursday.

Beleaguered shareholders of BP Plc who’ve watched their investment lag over the past few years are banking on activist Elliott Investment Management LP’s track record to help them extract some value from their positions.

The oil and gas major now has an influential activist investor. That puts even more pressure on CEO Murray Auchincloss.

Shares in BP rose by 7% on Monday, and were on track for the biggest daily gain in two years, as investors anticipated that activist shareholder Elliott Management will press for board changes and strategy shifts to boost returns.