The British wealth manager's CEO Mark FitzPatrick, who took up the role in December, announced a strategy update alongside half-year results, including a target to hit cumulative savings of close to 500 million pounds ($643 million) by 2030.
Analysts at JPMorgan said the cuts would lead to upgrades to the company's future earnings potential and welcomed a "very strong" set of earnings, including net inflows of 1.9 billion pounds that beat analysts' forecasts.
Its shares jumped as much as 25% in early trade to hit their highest in seven months and were up 20% by 0800 GMT, though they remain about 60% down on their January 2022 peak.
St James's Place said it would cut costs by 80 million pounds by 2026 and aim to trim its overall costs by 100 million pounds a year by 2027.
FitzPatrick told Reuters reducing the company's headcount would provide a "portion" of the cuts, without giving further details, but added technology and operational changes were also part of the mix.
Around half the savings will be invested back into the business, the company added, in areas including digital services and better serving ultra-wealthy clients.
"Through the refreshed strategy we'll drive growth in a stronger way," FitzPatrick said, adding that the firm planned to broaden its investment product range to include more passive, private markets and cash options for clients.
SJP's stock had been down around 40% over the past year, since Britain's top financial regulator announced a wider clampdown on firms to ensure they provide a fairer deal to customers.
The company is revamping its fee structure and working through customer complaints. The company said the amount it had previously set aside of 426 million pounds to cover potential redress costs remained appropriate.
It also reported total managed funds of 181.9 billion pounds and announced an interim dividend of 6 pence per share, down from last year's 15.83 pence. It also announced a share buyback of 32.9 million pounds.
"The market has been looking at SJP as a glass half empty and indeed emptying. The company has a very different view," said analysts at Liberum.
($1 = 0.7783 pounds)
($1 = 0.7782 pounds)
