Here's a TRIN chart using NYSE data. There has been no TRIN value over 4 since 12/28/2011. A low TRIN for an index occurs on a day when there is a small down volume diffused over many declining issues, while on the same day there is a large up volume which is concentrated in just a few issues. This is compatible with the fact that the capitalization of the top 10 companies was 15% of total market capitalization in 2011, growing to 36% in 2026
