In each round there is a minimum and maximum amount of buy as follows: 


Minimum amount: 150 USD (or its equivalent with Euro, GBP, BTC, BCH, ETH, XRP, ZEC, LTC, and USDT) 


Maximum amount: 25000 USD (or its equivalent with Euro, GBP, BTC, BCH, ETH, XRP, ZEC, LTC, and USDT) 


If you have reached the maximum level, you may wait till next round start.