Spread bets and CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. 76% of retail investor accounts lose money when trading spread bets and CFDs with this provider. You should consider whether you understand how spread bets and CFDs work and whether you can afford to take the high risk of losing your money.
If you have enough funds on your account, you can keep your trades open as long as you wish. Please note that if you use leveraged trading and a position remains open at the end of the day (after the market has closed), an overnight fee is charged.