You can earn $100 in 2 to 3 months without "base money" here but it will not be coming from trading. If you want to earn through trading, you will have to release a certain amount from your pocket. If you want to earn from zero financial capital then you will invest your services and effort in exchange of Bitcoin payment. If you start with $20 and invest it to BTC or ETH, your $100 will not come within the year. You choose some other new and cheap yet likely to pump.