but I don't think MOST calendar spreads have a trendy property.
When you use the term "calendar spreads", are you referring to a simple pair with two legs - same product / different month ? Are you lumping butterflies and condors into your assumption about trending ? Is there a particular reason ( like prop firm rules to get flat by the close ) that drives your brief holding time frames ?
Sorry for the follow-up questions, but I'm just trying to get some color about what's driving your frustration.
I used to trade size spreads here in Chicago for several years on an intraday basis ( prop firm ) and for long term ( HF and Commercial and now my own account).
My theory is that autospreaders are useless in agricultural space.