Bob Quigley duped people into parting with their savings by promising returns of up to 50% over five years.
He claimed his Buy-To-Let business would allow them to make big profits from booming land and property markets.
But when house prices collapsed, so did the hopes of the people who trusted him, Livingston Sheriff Court heard yesterday.
Quigley, 46, who was trading under the name of Lothian Property Portfolios, eventually admitted the game was up in June 2009.
He sent several investors a text from his mobile phone saying: "Truly sorry to tell you that I don't think I can go on like this. Goodnight, and God bless."
Quigley, whose £200,000 detached house in the Deer Park area of Livingston, West Lothian, is currently for sale, is now facing a lengthy prison sentence.
He pled guilty on indictment to illegally accepting cash deposits from people without being regulated by the Financial Services Authority.
He admitted accepting a total of £470,000 between October 2006 and February 2009 from five investors, whose addresses were given as c/o Police Scotland.
Quigley previously worked in the banking industry as a financial adviser with the Royal Bank of Scotland from 2001 to 2003.
He and his wife then founded a buy-to-let firm to invest in property in the West Lothian area.
Kevin Drugan, prosecuting, said the accused was approached by his brother-in-law Mark Baxter who gave him £50,000 to invest for growth after the business began to show signs of success.
Then Peter Noon, a friend of Quigley's sister, handed over nearly£153,000 for investment.
Mr Drugan said the affair started to unravel when Mr Noon demanded to know if the mortgage rate charged on his investment portfolio had been reduced to 0.5%, in line with market rates.
Mr Noon was sent the "Truly sorry" text message in June 2009, and was advised that the value of the investment properties - if sold - would not meet the mortgages secured against them.
John Lithgow, who had a property being managed by Quigley's company and agreed to invest £30,000 in development land in the Galashiels area received the same text message.
The biggest losers were Timothy Rice and his mother Sarah, who between them ploughed £240,000 into Quigley's unauthorised investment scheme.
Lorenzo Alonzi, defending, said his client had done everything properly by engaging lawyers to deal with the investments.
Mr Noon, 36, said: "We're all left with nothing. He still can't give me a straight answer as to where our money went."