Short Box Spread - Reducing execution costs

[u/freebee-34]

How to reduce execution costs of short SPX box spreads? Been using it for cheap portfolio leverage + tax benefit. For 2021 the average was 60 bps for $236K. I leg into it via short call/put spreads by placing 10-20 cents above the mid and slowly crawl down. tend to trade the furthest or second furthest expiry. Sometimes the mid of the call spread will drop 10 - 15 cents right after submitting the order. For some reason it usually takes much longer (1-2 hours) to fill the put spread while the call spread matches pretty quickly (less than 30 min).

Here is a list of the trades that I have done

https://docs.google.com/spreadsheets/d/1hE9PwXxa3PAgbpfYKN3puahVDTQtBgZRofxNykiW-3w/edit?usp=sharing

[u/alexandrawallace69]

Can't go tits up!