All sports betting providers limit the highest stakes. This is one way how the providers prevent betting fraud. The maximum amount depends on the bet and of course on the provider. In crazy outsider bets, such as the bet that Saudi Arabia will become soccer world champion, the maximum bet is usually a single-digit, at best double-digit amount. This way, the providers ensure that they are not accidentally bankrupt in the unlikely event of a very weird world cup. In normal games, the maximum amount is usually a good deal higher.