18.Concentrations of Risk

The Company’s revenues are concentrated in a small group of customers with some individually having more than 10% of total revenues.

Revenues from three customers that exceeded 10% of total revenues for the year ended December 31, 2020 were 45%,  22%, and 11%. The accounts receivable from the top three customers were 57%,  0%, and 0% as well as 12% from one other customer of the total accounts receivable as of December 31, 2020.

Revenues from four customers that exceeded 10% of total revenues for the year ended December 31, 2019 were 38%,  17%,  13% and 10%. Accounts receivable from these same four customers were 0%,  13%,  0% and 34% as well as 43% from three other customers of the total accounts receivable as of December 31, 2019.

The Company’s financial instruments that are exposed to concentrations of credit risk consist primarily of cash. Cash balances are maintained principally at major U.S. financial institutions and are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to regulatory limits. From time to time, cash balances may exceed the FDIC insurance limit. The Company has not experienced any credit losses associated with its cash balances in the past.