Yes, we extend the history of these relatively new ETFs by simulating them using the underlying GLD,TLT and SPY or even by using identical mutual funds which exist since the 1980’s. As you can not simply apply a 3x factor due to higher fees and rebalancing losses the factor is calculated so that we have the best chart match. Normally the factor is slightly below 3 for example 2.84x. These extended simulated price ranges are saved as cor files in QuantTrader.