Riot Blockchain says that COVID-19 will affect its cryptocurrency mining business in its annual report to the SEC
Source: https://cointelegraph.com/news/riot-blockchain-cites-covid-19-disruption-risks-on-sec-form-10-k
Riot Blockchain Cites COVID-19 Disruption Risks on SEC Form 10-K
March 30, 2020
CoinTelegraph