Since CFD Futures are derivative contracts based on the Futures market, they carry some of the same characteristics which includes expiry or rollover dates.
Each letter after the CFD symbol corresponds to a rollover or expiry month. Depending on the CFD, the months can be consecutive or periodic.
For example, the symbol for Crude Light with December 2014 expiry is CL.Z4. Crude Light expires monthly.
On the other hand, the symbol of Dow Jones with March 2015 expiry is DJ.H5. Index CFDs expire quarterly.
Why do CFD Futures charts on the Meta Trader 4 only go back a short period of time?
Since some CFD Futures contracts expire either monthly or quarterly, you can only go back and view the price movement history of a current CFD symbol from the time it started trading.