It has been brought to my attention by a very astute reader of the book that the ordering of the buy/sell/longliq/shortliq directives creates a potential error by giving preference to entries. The code in the book and my examples thus far test for a true condition first in the entry logic and then in the exit logic. Let’s say your long exit stop in the Euros is set at 11020, but your reversal is set at 11000. The python back tester will skip the exit at 11020 and reverse at 11000. This only happens if both stops are hit on the same day. If this happens you will incur a 20 point additional loss. You can prevent this by using logic similar to:
Notice bow I compare the price level of stb and stopb [stb – reversal and stopb – liquidation]. I added this to the long entry logic – the code is only executed if the entry is less than the exit (closer to the current market). I am in the process of restructuring the flow so that all orders will be examined on a bar by bar basis and the ones that should take place (chronologically speaking) will do so and be reflected in the performance metrics. This can cause multiple trades on a single bar. This is what happens in real trading and should be reflected in the PSB. This is where the lack of a GOTO creates a small headache in Python. The ESB already takes this into consieration. I will post when I finalize the code.
