I have been developing and testing several systems in the past few weeks with mixed results. The systems are performing well from 2007 - 2008.. in fact, they are performing extremely well. However, from 2006-2007 they go on losing streaks. I wanted to know if anyone else is having this issue with their back-tests. 2006 - 2007 is when the economy was going through an exceptionally turbulent economy (mortgage crisis, oil). To be fair, the economy still isn't good but at that time it was more of a surprise and reactions to the fundamentals were more exaggerated. I have several methods built into my systems to adjust entries and exits for volatility, but 2006-2007 is just really giving me a bashing. Despite this volatility adjusting, the systems are still losing from 2006-2007. I know that a lot of quantitative based funds took a hit during that year so I am fairly certain it is not just me. However, I am wondering how some of these quantitative systems have been adjusted to prepare for such an event at a future date.