Confidence in the equity market saw the shares held by retail investors reach a more than three-year high in May of £237bn.
Private shareholders added £798m of equity investment in the past three months, according to Capita Registrars in its latest analysis of UK share registers.
Capita said that its most recent findings showed the longest sustained period of net buying, with four consecutive quarters adding £2.3bn to investor holdings.
Charles Cryer, chief executive of Capita Registrars, said while private investors no longer own over half of the UK's listed companies – as they did 50 years ago – "equity ownership is not dying out. Private investors have recognised equities offer protection against inflation, the prospect of growth and a superior income to many other assets".