He said property and other "real assets", including gold, had been attractive investments in the past because the capital to buy them could be borrowed at a rate of interest much lower than the rate of inflation, and those assets tended to rise with inflation.
But he said that with the UK economy not currently "booming" and inflation not at the same level as had historically been the case, Mr Hargreaves said real assets were "less attractive".
He added: "Where property is concerned, there is a further factor weighing on its appeal - a punitive rate of stamp duty which has curbed property transactions.
"I am not convinced interest rates are going to rise with any significance in the short term, despite the Governor of the of the Bank of England indicating otherwise. In the UK we wouldn’t want the cost of borrowing or the value of the pound to rise the economy is not booming."
He said in the absence of value in those assets, and with bond markets also poor value, equities represented an opportunity.
Mr Hargreaves said: "I concede that shares seem expensive by historic standards, but the circumstances are unique. I believe a philosophy of holding cash with a view to invest further down the line would prove unfruitful, as opportunity after opportunity will be missed.
"Whilst other assets are poorly positioned, or have values so far inflated above that of the stock market, I believe an investment in the stock market at this very moment still seems like the sensible option."
Mr Hargreaves was estimated by the Sunday Times Rich list to have a personal wealth of £3.1bn. He said he has 90 per cent of his personal wealth invested in equities, most of which consists of a £2bn stake in the company he co-founded.
He is also a long standing investor in the Lindsell Train Global Equity fund, run by Nick Train.
Mr Hargreaves said he "puts his money where his mouth is", and this was a key reason for his decision to place £25m of his personal wealth in the Blue Whale Growth fund, a global equity mandate.
He said he has been motivated to invest in the fund because of his esteem for Stephen Yiu, the fund manager he described as "one of the hardest working people I have met".
The fund, which aims to become the "largest global fund around", has grown to £68m since launch.
Mr Hargreaves also recently invested £24m in the Goonhilly Earth Station in Cornwall, which provides spacecraft tracking services to satellite operators.
David Jane, who runs about £960m across four multi-asset funds at Miton Group, said he expected global inflation to rise so has been buying "hard assets" of the kind Mr Hargreaves is avoiding.
Ben Yearsley, investment director at Shore Capital said he "can’t get massively excited" about the outlook for UK property investments right now.
david.thorpe@ft.com
