From the announcement press release:
The S&P/BGCantor U.S. Treasury Inflation Protected Security Index is a broad, comprehensive, market value-weighted index that seeks to measure the performance of the U.S. Treasury Inflation-Protected Securities (TIPS) market.
You can track the index here, but since it just launched on Tuesday, there is very little to see except for the current numbers.
Treasury Inflation-Protected Securities 
It is true that I could have redeemed it when the rate was 1.9%, and maybe could have earned more…