A lone wolf terrorist is a single individual acting essentially alone who kills or injures people or inflicts or plans to inflict significant damage on infrastructure at a single instant or over time to bring about their political, religious, or ideological aims. SIMAD stands for Single Individual Massively Destructive – a lone wolf who uses or plans to use a weapon of mass destruction (WMD). The availability WMD's to individuals is increasing, for example, through the availability of synthetic biology. A Real Time Delphi study of the evolution of Lone Wolf terrorism was conducted with 57 worldwide experts. When the group was asked to estimate the year when a lone wolf might kill or wound 100,000 people in a single attack, the average response 2067. However, the group was sharply divided; self-identified security experts judged much later dates or “never.” While the severity of future attacks appears to be growing, the potential for pre-detection is also growing, giving rise to a new kind of arms race. This study provides early warning of a possibly serious and growing threat; the time should be used to help find strategies that can minimize the threat.