The American investor who stands to make a $6billion profit on Irish bonds has backed the country to produce ‘one of the best investments of the decade’.

California based trader Michael Hasenstab believes the turnaround in the Irish economy will be phenomenal and he is more than happy to profit from it.

Hasenstab also warned those traders who failed to follow his gamble that they will suffer ‘a fair amount of regret’.

As the holder of one of 10 of all Irish bonds, the 39-year-old partner at assets management company Franklin Templeton knows what he is talking about.

In an interview with the Irish Times newspaper, Hasenstab denied however that his holding of Irish government bonds was ‘driving’ the Irish bond market which is worth about $105 billion.

He told The Irish Times: “We bought a lot of Irish securities at very distressed prices which means someone was selling those bonds.

“I think there’s a fair amount of regret by some people who sold those at distressed prices when they are now trading at par [face value] or above par.

“I think there is also some regret from people who missed what I would argue is one of the best investments of the decade: the Irish turnaround.”

Hasenstab, who oversees $165 billion in investments for Franklin Templeton, began buying Irish government bonds in July 2011.

His move came as Ireland was downgraded to ‘junk’ status by credit rating agency Moody’s and bond yields were trading above 14 per cent.

The Irish Times explains: “Since then, as the company’s holding has risen to an estimated 10 per cent of the entire Irish sovereign bond market, yields have fallen to about 4 per cent.

“The accompanying rise in bond values leaves Franklin Templeton sitting on billions of euro of paper profit. Over the last 18 months, his funds have increased their purchase of Irish bonds in the secondary markets, while also participating in the NTMA’s primary issuance of Irish government bond earlier this year.

“During this period, yields on Irish government bonds have fallen to about 4 per cent.”

Hasenstab backs the belief that Ireland should get relief on its historical bank debt from the bail-out partners.

He said: “Ireland deserves it. Ireland is benefiting from the fact that it took the tough medicine upfront but the terms that they got from official support probably could be revisited.”