https://beta.finance.yahoo.com/news/negative-interest-rate-skepticism-grows-000100441.html
Commercial banks have long squealed about negative rates, which directly curtail profits by imposing a charge on their cash reserves, and the cries are getting louder. But it's the shifting mood among monetary officials and the fact that inflation has stayed stubbornly low that suggests the strategy may be running out of steam.
Negative rates come to the US: 1-month and 3-month Treasury bill yields are now negative
https://www.cnbc.com/2020/03/25/negative-rates-come-to-the-us-1-month-and-3-month-treasury-bill-yields-are-now-negative.html