Jeremy Silverstone, a financial adviser from Wimbledon, has won The Telegraph Fantasy Fund Competition, picking up a prize of £20,000.
Contestants, who were each given a £100,000 virtual portfolio, were challenged to generate the highest investment return they could on the imaginary money by choosing which funds to invest it in and how much to invest.
Mr Silverstone, 43, described the competition - which began on August 16 last year and didn't finish until the end of March, as a time-consuming "marathon".
He told the JC: "I would do research over weekends and then log on every weekday. Towards the end of the competition, I had to log on two or three times a day. Sometimes I had to stay up until 2am to watch Bloomberg in Asia".
By the end, he had taken his initial £100, 000 to more than £120,000, beating over 35,000 other contestants.
Mr Silverstone has worked in the finance sector since he was a teenager. He lived in Israel for four years from the age of 26, before returning to the UK and continuing his career.
In spite of his considerable experience in the sector, his triumph took him completely by surprise.
"In the last seven or eight days of the game, I had a good lead but nothing was guaranteed. You can lose very quickly. I was very excited but very nervous. I had to keep telling myself: 'don't give anything away, be ice cool, it's like poker, sometimes doing nothing is all you need to do'". He plans to spend part of the money on a holiday, but says that cash was not the primary reason for his entering the competition.
"Of course I was interested in the money. I would be lying if I said I wasn't, but the money won't make a direct difference to my life. It was more about the challenge; I liked the idea of winning and being the best".