T2D3 is a rule of thumb that defines best in class revenue growth. It postulates that from revenue in single-digit millions, revenue growth should triple for the first two years, then double for the subsequent three years. For example, a company that reaches $2M in revenue in year 0, should grow to $6m in year 1, $18m in year 2, $36m in year 3, $72m in year 4 and $144m in year 5. This thumb rule is based upon growth trajectories achieved by 50 hyper-growth technology companies.