We use chart to explain it which is from Aug 2011 while btc hit $30 in June 2011. That's why peter mention May 2011.
But again as we said that charts are like sea and analyst search pearls in that. You will find both and in chart. As a trader we should understand both and need to trade in short time frame. If you r investors than no need to woory bec btc history says that investors not face any loss if that hold btc 3+years.