MrBeast says he's borrowing money from his mom to pay for his wedding. There's a simple explanation.

MrBeast, or Jimmy Donaldson, doesn't like to keep a ton of cash on hand.

Amazon Prime/Beast Games

• YouTube sensation MrBeast said he's borrowing money from his mom to pay for his wedding.
• There's a simple explanation: he's focused on reinvesting his earnings to grow his business.
• MrBeast, also known as Jimmy Donaldson, recently reached the 400 million subscriber milestone.

MrBeast may be getting some financial help, but his 400 million fans shouldn't be surprised or concerned.