Can I quit work at age 40 by investing in an Isa?

Kwasi has been investing for three months into a stocks and shares individual savings account (Isa). Although his portfolio is worth a modest £8,000, he has set himself a big target. He says: "I turned 30 this year and in 10 years' time I'd like to be able to quit my current job, obtaining my income mainly from investments. I will then supplement this income with consultancy work."

He wants investment income of between £15,000 and £25,000 a year at age 40. To achieve this, he plans to invest between £1,000 and £2,000 a month, typically phasing his entry into positions in order to average out the cost incurred. He is also considering a buy-to-let investment in addition to his £500,000 home and moving his defined-contribution workplace pension to a self-invested personal pension (Sipp) where he can manage the money himself.

He says: "My experience initially began with the short selling of Northern Rock shares in 2008. I learned from this experience that speculative trading is far too stressful. I took a break and spent a considerable amount of time educating myself on investing. I have naturally gravitated towards the teachings of Ben Graham. I had to liquidate my assets in order to pay for my wedding in 2012 and the Royal Mail initial public offering (IPO) was the trigger for me getting back into the market.

"I have a high tolerance to risk. The only way I can save is via stocks and shares. I have never saved money in a savings account in my life."