Hi everybody!

I've noticed a performance degradation when trading index options (although this may not be exclusive to the index options). Have a look at the example below. The strategy simply buys 0.3/0.2 call spreads that are between 20 and 80 DTE. Initially, it is fast but as time passes it gets progressively slower.

The attached backtest filters calls between 0 and 90 DTE and is `completed in 545.06 seconds at 2k data points per second. Processing total of 898,112 data points.`. However, changing the filter from 90 to 45 DTE increases the speed from 2k datapoints per second o 24k. Another experiment that I did is simply comment out Buy (i.e. do everything except for buying the spread), while keeping the filter (0, 90) - this yields about 15k datapoints per second. 

My question is whether this is the expected speed given the size of the OptionChain or is there anything I can do to speed things up?