During the simulation there were forecasts being made as to when Bitcoin prices would fall. The increase in value of Bitcoin Enhanced is due to the results of those forecasts plus simple tracking the percentage change in Bitcoin prices at all other times. The 21,265% annual increase in Bitcoin Enhanced prices was a combination of these two factors: forecasting periods of price fall + tracking Bitcoin prices at all other times. Looking at the graph of live forecasts since 16th February 2018 may give you a better idea. The simulated results were calculated in exactly the same way as the live performance — the only difference being that the forecasts were not made before the event as they are for the live prices.