There is a minimum trade amount of $ 20, although you can choose to risk more if you'd like. (binaryoptionsu.com)
They can set their minimum and maximum trade amount limits and the time limit in which buyers are required to pay for an order. (smartmoneysmartliving.com)
You can have trading amounts at the click of a button in $ 80, $ 50, $ 20 and $ 10 denominations. (binaryj.com)