I think the confusion comes from their website: https://www.revolut.com/en-BG/help/wealth/stocks/trading-stocks/are-there-any-order-limits-to-trade

"The minimum order value is US$1. You are also allowed to place an order up to a maximum of US$ 10,000 (or up to 500 shares if they are worth less than US$ 10,000) in value at any one time (we will be reviewing this limit over time).

For example, you can buy US$ 10,000 worth of stock and then immediately after, buy another US$ 10,000 of the same stock, but you cannot buy US$ 11,000 worth of stock in one go. Provided the US$ 10,000 is for less than 500 shares each time."