Realtime Prices, Sentiment, Tweets, Scuttles, News and discussions on iPath S&P GSCI Crude Oil Total Return. iPath S&P GSCI Crude Oil Total Return Index ETN is a sub-index of the S&P GSCI Commodity Index. The S&P GSCI Crude Oil Total Return Index reflects the returns that are potentially available through an unleveraged investment in the West Texas Intermediate (WTI) crude oil futures contract plus the Treasury Bill rate of interest that could be earned on funds committed to the trading of the underlying contracts.