The Market  U.S. soybean prices have mostly been treading water these past few weeks with neither bulls nor bears able to get the upper hand for more than a few days. Continued trade war worries and challenges building negotiations between the U.S. and China have contributed to recent weakness in the soybean market, as has the weaker trend in soybean exports.  Perhaps more interesting than the futures action, which WPI readers will already be familiar with, is the gradual strengthening of basis levels in the Midwest. Basis bids for spot delivery against July futures have gradually firmed over the past five weeks, as occurred last year. This, however, is contrary to the usual seasonal trend of weaker basis and has helped this week&...