Corn's recent uptick, a countertrend rally within a secular downtrend, has been driven by an unusually wet planting season. The spring, likely influenced by the decreased output of the sun, has contributed to cooler and wetter planting season that's left millions of acres unplanted.
The invisible hand began leaning hard (selling/distributing) into the rally as of 5/28. That selling has not abated. In fact, it's intensified. Commercial traders contribution to DI has fallen to 1%; the lowest or maximum bearish reading is 0%. Corn's DI would have been lower than -72% had the retail investors not sold into the weakness. They still control over 3% of the Net Long position, so there's plenty of fuel to scatter the bulls. Retail investors are the weakest of the weak hands.
Corn's DI (Matrix Line 24)