We estimate dynamic volatility spillovers in the stock index futures market. Dynamic volatility spillovers build on Diebold and Yilmaz (2009, 2012). Volatility in UK (US) is a net receiver (transmitter) of shocks to futures volume. Bidirectional volatility spillovers between UK and US are identified. Open interest is a net receiver of shocks to futures volume in UK and US. Spot and futures volatilities adjust similarly to a shock in either market.