Simon Haydock, 49, was found not guilty of fraud by jury at Newport Crown Court.
It was claimed he had spent cash handed to him on high-risk investments and gambling.
But Mr Haydock, from Cardiff, had insisted that his mother Geraldine had told to him to “have the money and enjoy it” with his family.
His mother, who is in her 70s, had sold her home in Neath in 2010 and gave the money to her son to invest on her behalf.
The court heard the Mrs Haydock believed her son had “reinvested it against my wishes”.
But the jury cleared the managing director of Cascade wealth management of any wrong doing.