David Grin made his name and his fortune trading penny stocks. A US-Israeli hedge fund manager, he also profited from an investment in porn magazine Penthouse. But, in recent years, much of his efforts have been on property in Ireland. As chair of the Lotus Investment Group, he has lent out €364 million through 260 separate loans to help fund the completion of almost 3,000 houses. Run on a day-to-day basis in Ireland by Ian Lawlor, Lotus typically provides up to 70 per cent LTV of the site or property purchase and a further 70 per cent of the cost…