Stock indexes battled to erase early losses Wednesday as the final hour of trade approached. The Nasdaq trimmed a 1.8% loss to a 0.1%-to-0.3% sliver. The S&P 500 and the Dow Jones industrial average remained down 0.5% and 0.7%, respectively. Volume ran decisively higher, pointing to institutional activity. Starbucks (SBUX) was trying to turn a bad session into a constructive day, whittling a 2.5% loss into a 0.8% deficit.