Alex Roepers Atlantic Investment Management released strong mid-year numbers in a letter to investors, with the US equity-focused Cambrian Fund up 12.4% YTD net fees compared to 8.4% for the S&P 500, while Cambrian Global is up 6.8% YTD, just below the MSCI AC World TR, which is up 6.9% over the same period (last year, the top value investor had a return of over 38.3%) Atlantic also announced that its assets under management have grown to $2.3 billion as of July 16 from $1.9 billion at the end of 2013, split $1.7 billion in its US-based funds and $600 million in the…