Bull Sphere claims to be authorized and supervised by the US National Futures Association (NFA) with registration number 0548533. We indeed found a matching result in NFA's registry, however, Bull Sphere is not overseen by NFA as it is not an approved member of the regulator. As a forex trader, you must bear in mind that if a broker claims to be eligible to solicit US customers in forex activities, it must: 1) be accredited as an approved Forex Dealer Member of NFA; 2) be admitted as a "retail forex exchange dealer." Obviously, Bull Sphere doesn't satisfy these conditions. That means, this broker is merely a registered firm rather than a regulated one and is not qualified to carry out such services. Therefore, it is a scam.