To answer what you were probably going to look for in the link: peak was March 2020 (1.19), when Covid got real, bottom was April 2018 (0.067), don't know any particular significance of that month.
April 2018 sounds about right for the tech bubble peak - iirc softbank was still in full swing, everyone was "blitzscaling", it was peak exuberance. Not that the music stopped right after that, but even into 2019 things were starting to decline and the VC industry was getting slightly more conservative.
FED started raising interest rates in 2017[1]. The market didn't really start reacting until 2018, and by 2019 the FED got cold feet and was lowering rates again.
