Russell 2000 ETF put volume jumps on large October roll down

Russell 2000 ETF put volume jumps on large October roll down. Puts leading calls 2:1 in heavy volume this morning as the ETF trades down -2.91, or -1.53%, near $187.94. October puts dominate the action with a seller of nearly 70k Oct 179/181 put spreads for 36c, confirmed by Cboe open-close data to be a customer seller. 179s are bought to open, while the 181s appear to unwind a position opened on 8/14 when IWM was nearly $3 higher.