Bankroll challenge 50 into 10k at bovada something fishy!!

Currently doing a bankroll challenge turning $50 into $10,000.
Im now at nl5
Noticed some strange things going on the main thing which last night.
Extremely low player pools and guaranteed prize. How is this possible? Wouldn't the site go out of business extremely quick honoring these guarantees where they only collecting 20% required?Bankroll challenge 50 into 10k at bovada something fishy!!