Victims aged in their 20s have each lost an average of £8,900 after falling for investment scams that appear on image-sharing platform Instagram.
Action Fraud, a UK police-led awareness centre, said there had been a surge in activity in recent months by fraudsters posting about get-rich-quick schemes.
Victims are promised high returns within 24 hours, but the fraudsters demand fees and then disappear.
Some 356 reports of losses have been made in the past five months.
Those tricked lost