When Elliott Investment Management buys into a company to agitate for change, bankers and lawyers who have faced the hedge fund say executives can expect a strong view on their shortcomings, backed by meticulous research and financial firepower.

BP shares jumped early Monday following weekend reports that activist investor Elliott Management has built a stake in the struggling oil major.

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.